Vulnerabilities (CVE)

In the Linux kernel, the following vulnerability has been resolved: md/raid5: avoid BUG_ON() while continue reshape after reassembling Currently, mdadm support --revert-reshape to abort the reshape while reassembling, as the test 07revert-grow. However, following BUG_ON() can be triggerred by the test: kernel BUG at drivers/md/raid5.c:6278! invalid opcode: 0000 [#1] PREEMPT SMP PTI irq event stamp: 158985 CPU: 6 PID: 891 Comm: md0_reshape Not tainted 6.9.0-03335-g7592a0b0049a #94 RIP: 0010:re ... In the Linux kernel, the following vulnerability has been resolved: md/raid5: avoid BUG_ON() while continue reshape after reassembling Currently, mdadm support --revert-reshape to abort the reshape while reassembling, as the test 07revert-grow. However, following BUG_ON() can be triggerred by the test: kernel BUG at drivers/md/raid5.c:6278! invalid opcode: 0000 [#1] PREEMPT SMP PTI irq event stamp: 158985 CPU: 6 PID: 891 Comm: md0_reshape Not tainted 6.9.0-03335-g7592a0b0049a #94 RIP: 0010:reshape_request+0x3f1/0xe60 Call Trace: <TASK> raid5_sync_request+0x43d/0x550 md_do_sync+0xb7a/0x2110 md_thread+0x294/0x2b0 kthread+0x147/0x1c0 ret_from_fork+0x59/0x70 ret_from_fork_asm+0x1a/0x30 </TASK> Root cause is that --revert-reshape update the raid_disks from 5 to 4, while reshape position is still set, and after reassembling the array, reshape position will be read from super block, then during reshape the checking of 'writepos' that is caculated by old reshape position will fail. Fix this panic the easy way first, by converting the BUG_ON() to WARN_ON(), and stop the reshape if checkings fail. Noted that mdadm must fix --revert-shape as well, and probably md/raid should enhance metadata validation as well, however this means reassemble will fail and there must be user tools to fix the wrong metadata.

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In the Linux kernel, the following vulnerability has been resolved: wifi: nl80211: disallow setting special AP channel widths Setting the AP channel width is meant for use with the normal 20/40/... MHz channel width progression, and switching around in S1G or narrow channels isn't supported. Disallow that.

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: fix NULL dereference at band check in starting tx ba session In MLD connection, link_data/link_conf are dynamically allocated. They don't point to vif->bss_conf. So, there will be no chanreq assigned to vif->bss_conf and then the chan will be NULL. Tweak the code to check ht_supported/vht_supported/has_he/has_eht on sta deflink. Crash log (with rtw89 version under MLO development): [ 9890.526087] BUG: kernel N ... In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: fix NULL dereference at band check in starting tx ba session In MLD connection, link_data/link_conf are dynamically allocated. They don't point to vif->bss_conf. So, there will be no chanreq assigned to vif->bss_conf and then the chan will be NULL. Tweak the code to check ht_supported/vht_supported/has_he/has_eht on sta deflink. Crash log (with rtw89 version under MLO development): [ 9890.526087] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 9890.526102] #PF: supervisor read access in kernel mode [ 9890.526105] #PF: error_code(0x0000) - not-present page [ 9890.526109] PGD 0 P4D 0 [ 9890.526114] Oops: 0000 [#1] PREEMPT SMP PTI [ 9890.526119] CPU: 2 PID: 6367 Comm: kworker/u16:2 Kdump: loaded Tainted: G OE 6.9.0 #1 [ 9890.526123] Hardware name: LENOVO 2356AD1/2356AD1, BIOS G7ETB3WW (2.73 ) 11/28/2018 [ 9890.526126] Workqueue: phy2 rtw89_core_ba_work [rtw89_core] [ 9890.526203] RIP: 0010:ieee80211_start_tx_ba_session (net/mac80211/agg-tx.c:618 (discriminator 1)) mac80211 [ 9890.526279] Code: f7 e8 d5 93 3e ea 48 83 c4 28 89 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 49 8b 84 24 e0 f1 ff ff 48 8b 80 90 1b 00 00 <83> 38 03 0f 84 37 fe ff ff bb ea ff ff ff eb cc 49 8b 84 24 10 f3 All code ======== 0: f7 e8 imul %eax 2: d5 (bad) 3: 93 xchg %eax,%ebx 4: 3e ea ds (bad) 6: 48 83 c4 28 add $0x28,%rsp a: 89 d8 mov %ebx,%eax c: 5b pop %rbx d: 41 5c pop %r12 f: 41 5d pop %r13 11: 41 5e pop %r14 13: 41 5f pop %r15 15: 5d pop %rbp 16: c3 retq 17: cc int3 18: cc int3 19: cc int3 1a: cc int3 1b: 49 8b 84 24 e0 f1 ff mov -0xe20(%r12),%rax 22: ff 23: 48 8b 80 90 1b 00 00 mov 0x1b90(%rax),%rax 2a:* 83 38 03 cmpl $0x3,(%rax) <-- trapping instruction 2d: 0f 84 37 fe ff ff je 0xfffffffffffffe6a 33: bb ea ff ff ff mov $0xffffffea,%ebx 38: eb cc jmp 0x6 3a: 49 rex.WB 3b: 8b .byte 0x8b 3c: 84 24 10 test %ah,(%rax,%rdx,1) 3f: f3 repz Code starting with the faulting instruction =========================================== 0: 83 38 03 cmpl $0x3,(%rax) 3: 0f 84 37 fe ff ff je 0xfffffffffffffe40 9: bb ea ff ff ff mov $0xffffffea,%ebx e: eb cc jmp 0xffffffffffffffdc 10: 49 rex.WB 11: 8b .byte 0x8b 12: 84 24 10 test %ah,(%rax,%rdx,1) 15: f3 repz [ 9890.526285] RSP: 0018:ffffb8db09013d68 EFLAGS: 00010246 [ 9890.526291] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff9308e0d656c8 [ 9890.526295] RDX: 0000000000000000 RSI: ffffffffab99460b RDI: ffffffffab9a7685 [ 9890.526300] RBP: ffffb8db09013db8 R08: 0000000000000000 R09: 0000000000000873 [ 9890.526304] R10: ffff9308e0d64800 R11: 0000000000000002 R12: ffff9308e5ff6e70 [ 9890.526308] R13: ffff930952500e20 R14: ffff9309192a8c00 R15: 0000000000000000 [ 9890.526313] FS: 0000000000000000(0000) GS:ffff930b4e700000(0000) knlGS:0000000000000000 [ 9890.526316] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 9890.526318] CR2: 0000000000000000 CR3: 0000000391c58005 CR4: 00000000001706f0 [ 9890.526321] Call Trace: [ 9890.526324] <TASK> [ 9890.526327] ? show_regs (arch/x86/kernel/dumpstack.c:479) [ 9890.526335] ? __die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434) [ 9890.526340] ? page_fault_oops (arch/x86/mm/fault.c:713) [ 9890.526347] ? search_module_extables (kernel/module/main.c:3256 (discriminator ---truncated---

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In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/pm: Fix the null pointer dereference for smu7 optimize the code to avoid pass a null pointer (hwmgr->backend) to function smu7_update_edc_leakage_table.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix the null pointer dereference to ras_manager Check ras_manager before using it

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/pm: Fix the null pointer dereference in apply_state_adjust_rules Check the pointer value to fix potential null pointer dereference

In the Linux kernel, the following vulnerability has been resolved: drm/amd/pm: Fix the null pointer dereference for vega10_hwmgr Check return value and conduct null pointer handling to avoid null pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add null checks for 'stream' and 'plane' before dereferencing This commit adds null checks for the 'stream' and 'plane' variables in the dcn30_apply_idle_power_optimizations function. These variables were previously assumed to be null at line 922, but they were used later in the code without checking if they were null. This could potentially lead to a null pointer dereference, which would cause a crash. The n ... In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add null checks for 'stream' and 'plane' before dereferencing This commit adds null checks for the 'stream' and 'plane' variables in the dcn30_apply_idle_power_optimizations function. These variables were previously assumed to be null at line 922, but they were used later in the code without checking if they were null. This could potentially lead to a null pointer dereference, which would cause a crash. The null checks ensure that 'stream' and 'plane' are not null before they are used, preventing potential crashes. Fixes the below static smatch checker: drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn30/dcn30_hwseq.c:938 dcn30_apply_idle_power_optimizations() error: we previously assumed 'stream' could be null (see line 922) drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn30/dcn30_hwseq.c:940 dcn30_apply_idle_power_optimizations() error: we previously assumed 'plane' could be null (see line 922)

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In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add null checker before passing variables Checks null pointer before passing variables to functions. This fixes 3 NULL_RETURNS issues reported by Coverity.

In the Linux kernel, the following vulnerability has been resolved: media: xc2028: avoid use-after-free in load_firmware_cb() syzkaller reported use-after-free in load_firmware_cb() [1]. The reason is because the module allocated a struct tuner in tuner_probe(), and then the module initialization failed, the struct tuner was released. A worker which created during module initialization accesses this struct tuner later, it caused use-after-free. The process is as follows: task-6504 ... In the Linux kernel, the following vulnerability has been resolved: media: xc2028: avoid use-after-free in load_firmware_cb() syzkaller reported use-after-free in load_firmware_cb() [1]. The reason is because the module allocated a struct tuner in tuner_probe(), and then the module initialization failed, the struct tuner was released. A worker which created during module initialization accesses this struct tuner later, it caused use-after-free. The process is as follows: task-6504 worker_thread tuner_probe <= alloc dvb_frontend [2] ... request_firmware_nowait <= create a worker ... tuner_remove <= free dvb_frontend ... request_firmware_work_func <= the firmware is ready load_firmware_cb <= but now the dvb_frontend has been freed To fix the issue, check the dvd_frontend in load_firmware_cb(), if it is null, report a warning and just return. [1]: ================================================================== BUG: KASAN: use-after-free in load_firmware_cb+0x1310/0x17a0 Read of size 8 at addr ffff8000d7ca2308 by task kworker/2:3/6504 Call trace: load_firmware_cb+0x1310/0x17a0 request_firmware_work_func+0x128/0x220 process_one_work+0x770/0x1824 worker_thread+0x488/0xea0 kthread+0x300/0x430 ret_from_fork+0x10/0x20 Allocated by task 6504: kzalloc tuner_probe+0xb0/0x1430 i2c_device_probe+0x92c/0xaf0 really_probe+0x678/0xcd0 driver_probe_device+0x280/0x370 __device_attach_driver+0x220/0x330 bus_for_each_drv+0x134/0x1c0 __device_attach+0x1f4/0x410 device_initial_probe+0x20/0x30 bus_probe_device+0x184/0x200 device_add+0x924/0x12c0 device_register+0x24/0x30 i2c_new_device+0x4e0/0xc44 v4l2_i2c_new_subdev_board+0xbc/0x290 v4l2_i2c_new_subdev+0xc8/0x104 em28xx_v4l2_init+0x1dd0/0x3770 Freed by task 6504: kfree+0x238/0x4e4 tuner_remove+0x144/0x1c0 i2c_device_remove+0xc8/0x290 __device_release_driver+0x314/0x5fc device_release_driver+0x30/0x44 bus_remove_device+0x244/0x490 device_del+0x350/0x900 device_unregister+0x28/0xd0 i2c_unregister_device+0x174/0x1d0 v4l2_device_unregister+0x224/0x380 em28xx_v4l2_init+0x1d90/0x3770 The buggy address belongs to the object at ffff8000d7ca2000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 776 bytes inside of 2048-byte region [ffff8000d7ca2000, ffff8000d7ca2800) The buggy address belongs to the page: page:ffff7fe00035f280 count:1 mapcount:0 mapping:ffff8000c001f000 index:0x0 flags: 0x7ff800000000100(slab) raw: 07ff800000000100 ffff7fe00049d880 0000000300000003 ffff8000c001f000 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8000d7ca2200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8000d7ca2280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8000d7ca2300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8000d7ca2380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8000d7ca2400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== [2] Actually, it is allocated for struct tuner, and dvb_frontend is inside.

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In the Linux kernel, the following vulnerability has been resolved: net: drop bad gso csum_start and offset in virtio_net_hdr Tighten csum_start and csum_offset checks in virtio_net_hdr_to_skb for GSO packets. The function already checks that a checksum requested with VIRTIO_NET_HDR_F_NEEDS_CSUM is in skb linear. But for GSO packets this might not hold for segs after segmentation. Syzkaller demonstrated to reach this warning in skb_checksum_help offset = skb_checksum_start_offset(skb); re ... In the Linux kernel, the following vulnerability has been resolved: net: drop bad gso csum_start and offset in virtio_net_hdr Tighten csum_start and csum_offset checks in virtio_net_hdr_to_skb for GSO packets. The function already checks that a checksum requested with VIRTIO_NET_HDR_F_NEEDS_CSUM is in skb linear. But for GSO packets this might not hold for segs after segmentation. Syzkaller demonstrated to reach this warning in skb_checksum_help offset = skb_checksum_start_offset(skb); ret = -EINVAL; if (WARN_ON_ONCE(offset >= skb_headlen(skb))) By injecting a TSO packet: WARNING: CPU: 1 PID: 3539 at net/core/dev.c:3284 skb_checksum_help+0x3d0/0x5b0 ip_do_fragment+0x209/0x1b20 net/ipv4/ip_output.c:774 ip_finish_output_gso net/ipv4/ip_output.c:279 [inline] __ip_finish_output+0x2bd/0x4b0 net/ipv4/ip_output.c:301 iptunnel_xmit+0x50c/0x930 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x2296/0x2c70 net/ipv4/ip_tunnel.c:813 __gre_xmit net/ipv4/ip_gre.c:469 [inline] ipgre_xmit+0x759/0xa60 net/ipv4/ip_gre.c:661 __netdev_start_xmit include/linux/netdevice.h:4850 [inline] netdev_start_xmit include/linux/netdevice.h:4864 [inline] xmit_one net/core/dev.c:3595 [inline] dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3611 __dev_queue_xmit+0x1b97/0x3c90 net/core/dev.c:4261 packet_snd net/packet/af_packet.c:3073 [inline] The geometry of the bad input packet at tcp_gso_segment: [ 52.003050][ T8403] skb len=12202 headroom=244 headlen=12093 tailroom=0 [ 52.003050][ T8403] mac=(168,24) mac_len=24 net=(192,52) trans=244 [ 52.003050][ T8403] shinfo(txflags=0 nr_frags=1 gso(size=1552 type=3 segs=0)) [ 52.003050][ T8403] csum(0x60000c7 start=199 offset=1536 ip_summed=3 complete_sw=0 valid=0 level=0) Mitigate with stricter input validation. csum_offset: for GSO packets, deduce the correct value from gso_type. This is already done for USO. Extend it to TSO. Let UFO be: udp[46]_ufo_fragment ignores these fields and always computes the checksum in software. csum_start: finding the real offset requires parsing to the transport header. Do not add a parser, use existing segmentation parsing. Thanks to SKB_GSO_DODGY, that also catches bad packets that are hw offloaded. Again test both TSO and USO. Do not test UFO for the above reason, and do not test UDP tunnel offload. GSO packet are almost always CHECKSUM_PARTIAL. USO packets may be CHECKSUM_NONE since commit 10154dbded6d6 ("udp: Allow GSO transmit from devices with no checksum offload"), but then still these fields are initialized correctly in udp4_hwcsum/udp6_hwcsum_outgoing. So no need to test for ip_summed == CHECKSUM_PARTIAL first. This revises an existing fix mentioned in the Fixes tag, which broke small packets with GSO offload, as detected by kselftests.

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In the Linux kernel, the following vulnerability has been resolved: drm/client: fix null pointer dereference in drm_client_modeset_probe In drm_client_modeset_probe(), the return value of drm_mode_duplicate() is assigned to modeset->mode, which will lead to a possible NULL pointer dereference on failure of drm_mode_duplicate(). Add a check to avoid npd.

In the Linux kernel, the following vulnerability has been resolved: serial: core: check uartclk for zero to avoid divide by zero Calling ioctl TIOCSSERIAL with an invalid baud_base can result in uartclk being zero, which will result in a divide by zero error in uart_get_divisor(). The check for uartclk being zero in uart_set_info() needs to be done before other settings are made as subsequent calls to ioctl TIOCSSERIAL for the same port would be impacted if the uartclk check was done where uar ... In the Linux kernel, the following vulnerability has been resolved: serial: core: check uartclk for zero to avoid divide by zero Calling ioctl TIOCSSERIAL with an invalid baud_base can result in uartclk being zero, which will result in a divide by zero error in uart_get_divisor(). The check for uartclk being zero in uart_set_info() needs to be done before other settings are made as subsequent calls to ioctl TIOCSSERIAL for the same port would be impacted if the uartclk check was done where uartclk gets set. Oops: divide error: 0000 PREEMPT SMP KASAN PTI RIP: 0010:uart_get_divisor (drivers/tty/serial/serial_core.c:580) Call Trace: <TASK> serial8250_get_divisor (drivers/tty/serial/8250/8250_port.c:2576 drivers/tty/serial/8250/8250_port.c:2589) serial8250_do_set_termios (drivers/tty/serial/8250/8250_port.c:502 drivers/tty/serial/8250/8250_port.c:2741) serial8250_set_termios (drivers/tty/serial/8250/8250_port.c:2862) uart_change_line_settings (./include/linux/spinlock.h:376 ./include/linux/serial_core.h:608 drivers/tty/serial/serial_core.c:222) uart_port_startup (drivers/tty/serial/serial_core.c:342) uart_startup (drivers/tty/serial/serial_core.c:368) uart_set_info (drivers/tty/serial/serial_core.c:1034) uart_set_info_user (drivers/tty/serial/serial_core.c:1059) tty_set_serial (drivers/tty/tty_io.c:2637) tty_ioctl (drivers/tty/tty_io.c:2647 drivers/tty/tty_io.c:2791) __x64_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:907 fs/ioctl.c:893 fs/ioctl.c:893) do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Rule: add

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In the Linux kernel, the following vulnerability has been resolved: memcg: protect concurrent access to mem_cgroup_idr Commit 73f576c04b94 ("mm: memcontrol: fix cgroup creation failure after many small jobs") decoupled the memcg IDs from the CSS ID space to fix the cgroup creation failures. It introduced IDR to maintain the memcg ID space. The IDR depends on external synchronization mechanisms for modifications. For the mem_cgroup_idr, the idr_alloc() and idr_replace() happen within css cal ... In the Linux kernel, the following vulnerability has been resolved: memcg: protect concurrent access to mem_cgroup_idr Commit 73f576c04b94 ("mm: memcontrol: fix cgroup creation failure after many small jobs") decoupled the memcg IDs from the CSS ID space to fix the cgroup creation failures. It introduced IDR to maintain the memcg ID space. The IDR depends on external synchronization mechanisms for modifications. For the mem_cgroup_idr, the idr_alloc() and idr_replace() happen within css callback and thus are protected through cgroup_mutex from concurrent modifications. However idr_remove() for mem_cgroup_idr was not protected against concurrency and can be run concurrently for different memcgs when they hit their refcnt to zero. Fix that. We have been seeing list_lru based kernel crashes at a low frequency in our fleet for a long time. These crashes were in different part of list_lru code including list_lru_add(), list_lru_del() and reparenting code. Upon further inspection, it looked like for a given object (dentry and inode), the super_block's list_lru didn't have list_lru_one for the memcg of that object. The initial suspicions were either the object is not allocated through kmem_cache_alloc_lru() or somehow memcg_list_lru_alloc() failed to allocate list_lru_one() for a memcg but returned success. No evidence were found for these cases. Looking more deeply, we started seeing situations where valid memcg's id is not present in mem_cgroup_idr and in some cases multiple valid memcgs have same id and mem_cgroup_idr is pointing to one of them. So, the most reasonable explanation is that these situations can happen due to race between multiple idr_remove() calls or race between idr_alloc()/idr_replace() and idr_remove(). These races are causing multiple memcgs to acquire the same ID and then offlining of one of them would cleanup list_lrus on the system for all of them. Later access from other memcgs to the list_lru cause crashes due to missing list_lru_one.

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In the Linux kernel, the following vulnerability has been resolved: tracing: Fix overflow in get_free_elt() "tracing_map->next_elt" in get_free_elt() is at risk of overflowing. Once it overflows, new elements can still be inserted into the tracing_map even though the maximum number of elements (`max_elts`) has been reached. Continuing to insert elements after the overflow could result in the tracing_map containing "tracing_map->max_size" elements, leaving no empty entries. If any attempt is m ... In the Linux kernel, the following vulnerability has been resolved: tracing: Fix overflow in get_free_elt() "tracing_map->next_elt" in get_free_elt() is at risk of overflowing. Once it overflows, new elements can still be inserted into the tracing_map even though the maximum number of elements (`max_elts`) has been reached. Continuing to insert elements after the overflow could result in the tracing_map containing "tracing_map->max_size" elements, leaving no empty entries. If any attempt is made to insert an element into a full tracing_map using `__tracing_map_insert()`, it will cause an infinite loop with preemption disabled, leading to a CPU hang problem. Fix this by preventing any further increments to "tracing_map->next_elt" once it reaches "tracing_map->max_elt".

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In the Linux kernel, the following vulnerability has been resolved: padata: Fix possible divide-by-0 panic in padata_mt_helper() We are hit with a not easily reproducible divide-by-0 panic in padata.c at bootup time. [ 10.017908] Oops: divide error: 0000 1 PREEMPT SMP NOPTI [ 10.017908] CPU: 26 PID: 2627 Comm: kworker/u1666:1 Not tainted 6.10.0-15.el10.x86_64 #1 [ 10.017908] Hardware name: Lenovo ThinkSystem SR950 [7X12CTO1WW]/[7X12CTO1WW], BIOS [PSE140J-2.30] 07/20/2021 [ 10. ... In the Linux kernel, the following vulnerability has been resolved: padata: Fix possible divide-by-0 panic in padata_mt_helper() We are hit with a not easily reproducible divide-by-0 panic in padata.c at bootup time. [ 10.017908] Oops: divide error: 0000 1 PREEMPT SMP NOPTI [ 10.017908] CPU: 26 PID: 2627 Comm: kworker/u1666:1 Not tainted 6.10.0-15.el10.x86_64 #1 [ 10.017908] Hardware name: Lenovo ThinkSystem SR950 [7X12CTO1WW]/[7X12CTO1WW], BIOS [PSE140J-2.30] 07/20/2021 [ 10.017908] Workqueue: events_unbound padata_mt_helper [ 10.017908] RIP: 0010:padata_mt_helper+0x39/0xb0 : [ 10.017963] Call Trace: [ 10.017968] <TASK> [ 10.018004] ? padata_mt_helper+0x39/0xb0 [ 10.018084] process_one_work+0x174/0x330 [ 10.018093] worker_thread+0x266/0x3a0 [ 10.018111] kthread+0xcf/0x100 [ 10.018124] ret_from_fork+0x31/0x50 [ 10.018138] ret_from_fork_asm+0x1a/0x30 [ 10.018147] </TASK> Looking at the padata_mt_helper() function, the only way a divide-by-0 panic can happen is when ps->chunk_size is 0. The way that chunk_size is initialized in padata_do_multithreaded(), chunk_size can be 0 when the min_chunk in the passed-in padata_mt_job structure is 0. Fix this divide-by-0 panic by making sure that chunk_size will be at least 1 no matter what the input parameters are.

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In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: Add error handling to pair_device() hci_conn_params_add() never checks for a NULL value and could lead to a NULL pointer dereference causing a crash. Fixed by adding error handling in the function.

In the Linux kernel, the following vulnerability has been resolved: usb: vhci-hcd: Do not drop references before new references are gained At a few places the driver carries stale pointers to references that can still be used. Make sure that does not happen. This strictly speaking closes ZDI-CAN-22273, though there may be similar races in the driver.

In the Linux kernel, the following vulnerability has been resolved: exec: Fix ToCToU between perm check and set-uid/gid usage When opening a file for exec via do_filp_open(), permission checking is done against the file's metadata at that moment, and on success, a file pointer is passed back. Much later in the execve() code path, the file metadata (specifically mode, uid, and gid) is used to determine if/how to set the uid and gid. However, those values may have changed since the permissions c ... In the Linux kernel, the following vulnerability has been resolved: exec: Fix ToCToU between perm check and set-uid/gid usage When opening a file for exec via do_filp_open(), permission checking is done against the file's metadata at that moment, and on success, a file pointer is passed back. Much later in the execve() code path, the file metadata (specifically mode, uid, and gid) is used to determine if/how to set the uid and gid. However, those values may have changed since the permissions check, meaning the execution may gain unintended privileges. For example, if a file could change permissions from executable and not set-id: ---------x 1 root root 16048 Aug 7 13:16 target to set-id and non-executable: ---S------ 1 root root 16048 Aug 7 13:16 target it is possible to gain root privileges when execution should have been disallowed. While this race condition is rare in real-world scenarios, it has been observed (and proven exploitable) when package managers are updating the setuid bits of installed programs. Such files start with being world-executable but then are adjusted to be group-exec with a set-uid bit. For example, "chmod o-x,u+s target" makes "target" executable only by uid "root" and gid "cdrom", while also becoming setuid-root: -rwxr-xr-x 1 root cdrom 16048 Aug 7 13:16 target becomes: -rwsr-xr-- 1 root cdrom 16048 Aug 7 13:16 target But racing the chmod means users without group "cdrom" membership can get the permission to execute "target" just before the chmod, and when the chmod finishes, the exec reaches brpm_fill_uid(), and performs the setuid to root, violating the expressed authorization of "only cdrom group members can setuid to root". Re-check that we still have execute permissions in case the metadata has changed. It would be better to keep a copy from the perm-check time, but until we can do that refactoring, the least-bad option is to do a full inode_permission() call (under inode lock). It is understood that this is safe against dead-locks, but hardly optimal.

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In the Linux kernel, the following vulnerability has been resolved: mlxsw: spectrum_acl_erp: Fix object nesting warning ACLs in Spectrum-2 and newer ASICs can reside in the algorithmic TCAM (A-TCAM) or in the ordinary circuit TCAM (C-TCAM). The former can contain more ACLs (i.e., tc filters), but the number of masks in each region (i.e., tc chain) is limited. In order to mitigate the effects of the above limitation, the device allows filters to share a single mask if their masks only differ i ... In the Linux kernel, the following vulnerability has been resolved: mlxsw: spectrum_acl_erp: Fix object nesting warning ACLs in Spectrum-2 and newer ASICs can reside in the algorithmic TCAM (A-TCAM) or in the ordinary circuit TCAM (C-TCAM). The former can contain more ACLs (i.e., tc filters), but the number of masks in each region (i.e., tc chain) is limited. In order to mitigate the effects of the above limitation, the device allows filters to share a single mask if their masks only differ in up to 8 consecutive bits. For example, dst_ip/25 can be represented using dst_ip/24 with a delta of 1 bit. The C-TCAM does not have a limit on the number of masks being used (and therefore does not support mask aggregation), but can contain a limited number of filters. The driver uses the "objagg" library to perform the mask aggregation by passing it objects that consist of the filter's mask and whether the filter is to be inserted into the A-TCAM or the C-TCAM since filters in different TCAMs cannot share a mask. The set of created objects is dependent on the insertion order of the filters and is not necessarily optimal. Therefore, the driver will periodically ask the library to compute a more optimal set ("hints") by looking at all the existing objects. When the library asks the driver whether two objects can be aggregated the driver only compares the provided masks and ignores the A-TCAM / C-TCAM indication. This is the right thing to do since the goal is to move as many filters as possible to the A-TCAM. The driver also forbids two identical masks from being aggregated since this can only happen if one was intentionally put in the C-TCAM to avoid a conflict in the A-TCAM. The above can result in the following set of hints: H1: {mask X, A-TCAM} -> H2: {mask Y, A-TCAM} // X is Y + delta H3: {mask Y, C-TCAM} -> H4: {mask Z, A-TCAM} // Y is Z + delta After getting the hints from the library the driver will start migrating filters from one region to another while consulting the computed hints and instructing the device to perform a lookup in both regions during the transition. Assuming a filter with mask X is being migrated into the A-TCAM in the new region, the hints lookup will return H1. Since H2 is the parent of H1, the library will try to find the object associated with it and create it if necessary in which case another hints lookup (recursive) will be performed. This hints lookup for {mask Y, A-TCAM} will either return H2 or H3 since the driver passes the library an object comparison function that ignores the A-TCAM / C-TCAM indication. This can eventually lead to nested objects which are not supported by the library [1]. Fix by removing the object comparison function from both the driver and the library as the driver was the only user. That way the lookup will only return exact matches. I do not have a reliable reproducer that can reproduce the issue in a timely manner, but before the fix the issue would reproduce in several minutes and with the fix it does not reproduce in over an hour. Note that the current usefulness of the hints is limited because they include the C-TCAM indication and represent aggregation that cannot actually happen. This will be addressed in net-next. [1] WARNING: CPU: 0 PID: 153 at lib/objagg.c:170 objagg_obj_parent_assign+0xb5/0xd0 Modules linked in: CPU: 0 PID: 153 Comm: kworker/0:18 Not tainted 6.9.0-rc6-custom-g70fbc2c1c38b #42 Hardware name: Mellanox Technologies Ltd. MSN3700C/VMOD0008, BIOS 5.11 10/10/2018 Workqueue: mlxsw_core mlxsw_sp_acl_tcam_vregion_rehash_work RIP: 0010:objagg_obj_parent_assign+0xb5/0xd0 [...] Call Trace: <TASK> __objagg_obj_get+0x2bb/0x580 objagg_obj_get+0xe/0x80 mlxsw_sp_acl_erp_mask_get+0xb5/0xf0 mlxsw_sp_acl_atcam_entry_add+0xe8/0x3c0 mlxsw_sp_acl_tcam_entry_create+0x5e/0xa0 mlxsw_sp_acl_tcam_vchunk_migrate_one+0x16b/0x270 mlxsw_sp_acl_tcam_vregion_rehash_work+0xbe/0x510 process_one_work+0x151/0x370

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In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: handle 2x996 RU allocation in cfg80211_calculate_bitrate_he() Currently NL80211_RATE_INFO_HE_RU_ALLOC_2x996 is not handled in cfg80211_calculate_bitrate_he(), leading to below warning: kernel: invalid HE MCS: bw:6, ru:6 kernel: WARNING: CPU: 0 PID: 2312 at net/wireless/util.c:1501 cfg80211_calculate_bitrate_he+0x22b/0x270 [cfg80211] Fix it by handling 2x996 RU allocation in the same way as 160 MHz bandwidth.

In the Linux kernel, the following vulnerability has been resolved: media: pci: ivtv: Add check for DMA map result In case DMA fails, 'dma->SG_length' is 0. This value is later used to access 'dma->SGarray[dma->SG_length - 1]', which will cause out of bounds access. Add check to return early on invalid value. Adjust warnings accordingly. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: PCI: rcar: Demote WARN() to dev_warn_ratelimited() in rcar_pcie_wakeup() Avoid large backtrace, it is sufficient to warn the user that there has been a link problem. Either the link has failed and the system is in need of maintenance, or the link continues to work and user has been informed. The message from the warning can be looked up in the sources. This makes an actual link issue less verbose. First of all, this controll ... In the Linux kernel, the following vulnerability has been resolved: PCI: rcar: Demote WARN() to dev_warn_ratelimited() in rcar_pcie_wakeup() Avoid large backtrace, it is sufficient to warn the user that there has been a link problem. Either the link has failed and the system is in need of maintenance, or the link continues to work and user has been informed. The message from the warning can be looked up in the sources. This makes an actual link issue less verbose. First of all, this controller has a limitation in that the controller driver has to assist the hardware with transition to L1 link state by writing L1IATN to PMCTRL register, the L1 and L0 link state switching is not fully automatic on this controller. In case of an ASMedia ASM1062 PCIe SATA controller which does not support ASPM, on entry to suspend or during platform pm_test, the SATA controller enters D3hot state and the link enters L1 state. If the SATA controller wakes up before rcar_pcie_wakeup() was called and returns to D0, the link returns to L0 before the controller driver even started its transition to L1 link state. At this point, the SATA controller did send an PM_ENTER_L1 DLLP to the PCIe controller and the PCIe controller received it, and the PCIe controller did set PMSR PMEL1RX bit. Once rcar_pcie_wakeup() is called, if the link is already back in L0 state and PMEL1RX bit is set, the controller driver has no way to determine if it should perform the link transition to L1 state, or treat the link as if it is in L0 state. Currently the driver attempts to perform the transition to L1 link state unconditionally, which in this specific case fails with a PMSR L1FAEG poll timeout, however the link still works as it is already back in L0 state. Reduce this warning verbosity. In case the link is really broken, the rcar_pcie_config_access() would fail, otherwise it will succeed and any system with this controller and ASM1062 can suspend without generating a backtrace.

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In the Linux kernel, the following vulnerability has been resolved: PCI: endpoint: Clean up error handling in vpci_scan_bus() Smatch complains about inconsistent NULL checking in vpci_scan_bus(): drivers/pci/endpoint/functions/pci-epf-vntb.c:1024 vpci_scan_bus() error: we previously assumed 'vpci_bus' could be null (see line 1021) Instead of printing an error message and then crashing we should return an error code and clean up. Also the NULL check is reversed so it prints an error for ... In the Linux kernel, the following vulnerability has been resolved: PCI: endpoint: Clean up error handling in vpci_scan_bus() Smatch complains about inconsistent NULL checking in vpci_scan_bus(): drivers/pci/endpoint/functions/pci-epf-vntb.c:1024 vpci_scan_bus() error: we previously assumed 'vpci_bus' could be null (see line 1021) Instead of printing an error message and then crashing we should return an error code and clean up. Also the NULL check is reversed so it prints an error for success instead of failure.

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In the Linux kernel, the following vulnerability has been resolved: vhost/vsock: always initialize seqpacket_allow There are two issues around seqpacket_allow: 1. seqpacket_allow is not initialized when socket is created. Thus if features are never set, it will be read uninitialized. 2. if VIRTIO_VSOCK_F_SEQPACKET is set and then cleared, then seqpacket_allow will not be cleared appropriately (existing apps I know about don't usually do this but it's legal and there's no way to ... In the Linux kernel, the following vulnerability has been resolved: vhost/vsock: always initialize seqpacket_allow There are two issues around seqpacket_allow: 1. seqpacket_allow is not initialized when socket is created. Thus if features are never set, it will be read uninitialized. 2. if VIRTIO_VSOCK_F_SEQPACKET is set and then cleared, then seqpacket_allow will not be cleared appropriately (existing apps I know about don't usually do this but it's legal and there's no way to be sure no one relies on this). To fix: - initialize seqpacket_allow after allocation - set it unconditionally in set_features

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In the Linux kernel, the following vulnerability has been resolved: devres: Fix memory leakage caused by driver API devm_free_percpu() It will cause memory leakage when use driver API devm_free_percpu() to free memory allocated by devm_alloc_percpu(), fixed by using devres_release() instead of devres_destroy() within devm_free_percpu().

In the Linux kernel, the following vulnerability has been resolved: perf: Fix event leak upon exit When a task is scheduled out, pending sigtrap deliveries are deferred to the target task upon resume to userspace via task_work. However failures while adding an event's callback to the task_work engine are ignored. And since the last call for events exit happen after task work is eventually closed, there is a small window during which pending sigtrap can be queued though ignored, leaking the ev ... In the Linux kernel, the following vulnerability has been resolved: perf: Fix event leak upon exit When a task is scheduled out, pending sigtrap deliveries are deferred to the target task upon resume to userspace via task_work. However failures while adding an event's callback to the task_work engine are ignored. And since the last call for events exit happen after task work is eventually closed, there is a small window during which pending sigtrap can be queued though ignored, leaking the event refcount addition such as in the following scenario: TASK A ----- do_exit() exit_task_work(tsk); <IRQ> perf_event_overflow() event->pending_sigtrap = pending_id; irq_work_queue(&event->pending_irq); </IRQ> =========> PREEMPTION: TASK A -> TASK B event_sched_out() event->pending_sigtrap = 0; atomic_long_inc_not_zero(&event->refcount) // FAILS: task work has exited task_work_add(&event->pending_task) [...] <IRQ WORK> perf_pending_irq() // early return: event->oncpu = -1 </IRQ WORK> [...] =========> TASK B -> TASK A perf_event_exit_task(tsk) perf_event_exit_event() free_event() WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1) // leak event due to unexpected refcount == 2 As a result the event is never released while the task exits. Fix this with appropriate task_work_add()'s error handling.

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In the Linux kernel, the following vulnerability has been resolved: perf: Fix event leak upon exec and file release The perf pending task work is never waited upon the matching event release. In the case of a child event, released via free_event() directly, this can potentially result in a leaked event, such as in the following scenario that doesn't even require a weak IRQ work implementation to trigger: schedule() prepare_task_switch() =======> <NMI> perf_event_overflow() e ... In the Linux kernel, the following vulnerability has been resolved: perf: Fix event leak upon exec and file release The perf pending task work is never waited upon the matching event release. In the case of a child event, released via free_event() directly, this can potentially result in a leaked event, such as in the following scenario that doesn't even require a weak IRQ work implementation to trigger: schedule() prepare_task_switch() =======> <NMI> perf_event_overflow() event->pending_sigtrap = ... irq_work_queue(&event->pending_irq) <======= </NMI> perf_event_task_sched_out() event_sched_out() event->pending_sigtrap = 0; atomic_long_inc_not_zero(&event->refcount) task_work_add(&event->pending_task) finish_lock_switch() =======> <IRQ> perf_pending_irq() //do nothing, rely on pending task work <======= </IRQ> begin_new_exec() perf_event_exit_task() perf_event_exit_event() // If is child event free_event() WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1) // event is leaked Similar scenarios can also happen with perf_event_remove_on_exec() or simply against concurrent perf_event_release(). Fix this with synchonizing against the possibly remaining pending task work while freeing the event, just like is done with remaining pending IRQ work. This means that the pending task callback neither need nor should hold a reference to the event, preventing it from ever beeing freed.

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In the Linux kernel, the following vulnerability has been resolved: riscv/purgatory: align riscv_kernel_entry When alignment handling is delegated to the kernel, everything must be word-aligned in purgatory, since the trap handler is then set to the kexec one. Without the alignment, hitting the exception would ultimately crash. On other occasions, the kernel's handler would take care of exceptions. This has been tested on a JH7110 SoC with oreboot and its SBI delegating unaligned access except ... In the Linux kernel, the following vulnerability has been resolved: riscv/purgatory: align riscv_kernel_entry When alignment handling is delegated to the kernel, everything must be word-aligned in purgatory, since the trap handler is then set to the kexec one. Without the alignment, hitting the exception would ultimately crash. On other occasions, the kernel's handler would take care of exceptions. This has been tested on a JH7110 SoC with oreboot and its SBI delegating unaligned access exceptions and the kernel configured to handle them.

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In the Linux kernel, the following vulnerability has been resolved: drm/nouveau: prime: fix refcount underflow Calling nouveau_bo_ref() on a nouveau_bo without initializing it (and hence the backing ttm_bo) leads to a refcount underflow. Instead of calling nouveau_bo_ref() in the unwind path of drm_gem_object_init(), clean things up manually. (cherry picked from commit 1b93f3e89d03cfc576636e195466a0d728ad8de5)

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Always drain health in shutdown callback There is no point in recovery during device shutdown. if health work started need to wait for it to avoid races and NULL pointer access. Hence, drain health WQ on shutdown callback.

In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: Fix a deadlock in dma buf fence polling Introduce a version of the fence ops that on release doesn't remove the fence from the pending list, and thus doesn't require a lock to fix poll->fence wait->fence unref deadlocks. vmwgfx overwrites the wait callback to iterate over the list of all fences and update their status, to do that it holds a lock to prevent the list modifcations from other threads. The fence destro ... In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: Fix a deadlock in dma buf fence polling Introduce a version of the fence ops that on release doesn't remove the fence from the pending list, and thus doesn't require a lock to fix poll->fence wait->fence unref deadlocks. vmwgfx overwrites the wait callback to iterate over the list of all fences and update their status, to do that it holds a lock to prevent the list modifcations from other threads. The fence destroy callback both deletes the fence and removes it from the list of pending fences, for which it holds a lock. dma buf polling cb unrefs a fence after it's been signaled: so the poll calls the wait, which signals the fences, which are being destroyed. The destruction tries to acquire the lock on the pending fences list which it can never get because it's held by the wait from which it was called. Old bug, but not a lot of userspace apps were using dma-buf polling interfaces. Fix those, in particular this fixes KDE stalls/deadlock.

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In the Linux kernel, the following vulnerability has been resolved: net: usb: qmi_wwan: fix memory leak for not ip packets Free the unused skb when not ip packets arrive.

In the Linux kernel, the following vulnerability has been resolved: remoteproc: imx_rproc: Skip over memory region when node value is NULL In imx_rproc_addr_init() "nph = of_count_phandle_with_args()" just counts number of phandles. But phandles may be empty. So of_parse_phandle() in the parsing loop (0 < a < nph) may return NULL which is later dereferenced. Adjust this issue by adding NULL-return check. Found by Linux Verification Center (linuxtesting.org) with SVACE. [Fixed title to fit wi ... In the Linux kernel, the following vulnerability has been resolved: remoteproc: imx_rproc: Skip over memory region when node value is NULL In imx_rproc_addr_init() "nph = of_count_phandle_with_args()" just counts number of phandles. But phandles may be empty. So of_parse_phandle() in the parsing loop (0 < a < nph) may return NULL which is later dereferenced. Adjust this issue by adding NULL-return check. Found by Linux Verification Center (linuxtesting.org) with SVACE. [Fixed title to fit within the prescribed 70-75 charcters]

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In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to truncate preallocated blocks in f2fs_file_open() chenyuwen reports a f2fs bug as below: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000011 fscrypt_set_bio_crypt_ctx+0x78/0x1e8 f2fs_grab_read_bio+0x78/0x208 f2fs_submit_page_read+0x44/0x154 f2fs_get_read_data_page+0x288/0x5f4 f2fs_get_lock_data_page+0x60/0x190 truncate_partial_data_page+0x108/0x4fc f2fs_do_truncate_blocks+0x ... In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to truncate preallocated blocks in f2fs_file_open() chenyuwen reports a f2fs bug as below: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000011 fscrypt_set_bio_crypt_ctx+0x78/0x1e8 f2fs_grab_read_bio+0x78/0x208 f2fs_submit_page_read+0x44/0x154 f2fs_get_read_data_page+0x288/0x5f4 f2fs_get_lock_data_page+0x60/0x190 truncate_partial_data_page+0x108/0x4fc f2fs_do_truncate_blocks+0x344/0x5f0 f2fs_truncate_blocks+0x6c/0x134 f2fs_truncate+0xd8/0x200 f2fs_iget+0x20c/0x5ac do_garbage_collect+0x5d0/0xf6c f2fs_gc+0x22c/0x6a4 f2fs_disable_checkpoint+0xc8/0x310 f2fs_fill_super+0x14bc/0x1764 mount_bdev+0x1b4/0x21c f2fs_mount+0x20/0x30 legacy_get_tree+0x50/0xbc vfs_get_tree+0x5c/0x1b0 do_new_mount+0x298/0x4cc path_mount+0x33c/0x5fc __arm64_sys_mount+0xcc/0x15c invoke_syscall+0x60/0x150 el0_svc_common+0xb8/0xf8 do_el0_svc+0x28/0xa0 el0_svc+0x24/0x84 el0t_64_sync_handler+0x88/0xec It is because inode.i_crypt_info is not initialized during below path: - mount - f2fs_fill_super - f2fs_disable_checkpoint - f2fs_gc - f2fs_iget - f2fs_truncate So, let's relocate truncation of preallocated blocks to f2fs_file_open(), after fscrypt_file_open().

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In the Linux kernel, the following vulnerability has been resolved: jfs: Fix array-index-out-of-bounds in diFree

In the Linux kernel, the following vulnerability has been resolved: dma: fix call order in dmam_free_coherent dmam_free_coherent() frees a DMA allocation, which makes the freed vaddr available for reuse, then calls devres_destroy() to remove and free the data structure used to track the DMA allocation. Between the two calls, it is possible for a concurrent task to make an allocation with the same vaddr and add it to the devres list. If this happens, there will be two entries in the devres lis ... In the Linux kernel, the following vulnerability has been resolved: dma: fix call order in dmam_free_coherent dmam_free_coherent() frees a DMA allocation, which makes the freed vaddr available for reuse, then calls devres_destroy() to remove and free the data structure used to track the DMA allocation. Between the two calls, it is possible for a concurrent task to make an allocation with the same vaddr and add it to the devres list. If this happens, there will be two entries in the devres list with the same vaddr and devres_destroy() can free the wrong entry, triggering the WARN_ON() in dmam_match. Fix by destroying the devres entry before freeing the DMA allocation. kokonut //net/encryption http://sponge2/b9145fe6-0f72-4325-ac2f-a84d81075b03

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In the Linux kernel, the following vulnerability has been resolved: md: fix deadlock between mddev_suspend and flush bio Deadlock occurs when mddev is being suspended while some flush bio is in progress. It is a complex issue. T1. the first flush is at the ending stage, it clears 'mddev->flush_bio' and tries to submit data, but is blocked because mddev is suspended by T4. T2. the second flush sets 'mddev->flush_bio', and attempts to queue md_submit_flush_data(), which is already r ... In the Linux kernel, the following vulnerability has been resolved: md: fix deadlock between mddev_suspend and flush bio Deadlock occurs when mddev is being suspended while some flush bio is in progress. It is a complex issue. T1. the first flush is at the ending stage, it clears 'mddev->flush_bio' and tries to submit data, but is blocked because mddev is suspended by T4. T2. the second flush sets 'mddev->flush_bio', and attempts to queue md_submit_flush_data(), which is already running (T1) and won't execute again if on the same CPU as T1. T3. the third flush inc active_io and tries to flush, but is blocked because 'mddev->flush_bio' is not NULL (set by T2). T4. mddev_suspend() is called and waits for active_io dec to 0 which is inc by T3. T1 T2 T3 T4 (flush 1) (flush 2) (third 3) (suspend) md_submit_flush_data mddev->flush_bio = NULL; . . md_flush_request . mddev->flush_bio = bio . queue submit_flushes . . . . md_handle_request . . active_io + 1 . . md_flush_request . . wait !mddev->flush_bio . . . . mddev_suspend . . wait !active_io . . . submit_flushes . queue_work md_submit_flush_data . //md_submit_flush_data is already running (T1) . md_handle_request wait resume The root issue is non-atomic inc/dec of active_io during flush process. active_io is dec before md_submit_flush_data is queued, and inc soon after md_submit_flush_data() run. md_flush_request active_io + 1 submit_flushes active_io - 1 md_submit_flush_data md_handle_request active_io + 1 make_request active_io - 1 If active_io is dec after md_handle_request() instead of within submit_flushes(), make_request() can be called directly intead of md_handle_request() in md_submit_flush_data(), and active_io will only inc and dec once in the whole flush process. Deadlock will be fixed. Additionally, the only difference between fixing the issue and before is that there is no return error handling of make_request(). But after previous patch cleaned md_write_start(), make_requst() only return error in raid5_make_request() by dm-raid, see commit 41425f96d7aa ("dm-raid456, md/raid456: fix a deadlock for dm-raid456 while io concurrent with reshape)". Since dm always splits data and flush operation into two separate io, io size of flush submitted by dm always is 0, make_request() will not be called in md_submit_flush_data(). To prevent future modifications from introducing issues, add WARN_ON to ensure make_request() no error is returned in this context.

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In the Linux kernel, the following vulnerability has been resolved: block: initialize integrity buffer to zero before writing it to media Metadata added by bio_integrity_prep is using plain kmalloc, which leads to random kernel memory being written media. For PI metadata this is limited to the app tag that isn't used by kernel generated metadata, but for non-PI metadata the entire buffer leaks kernel memory. Fix this by adding the __GFP_ZERO flag to allocations for writes.

In the Linux kernel, the following vulnerability has been resolved: cgroup/cpuset: Prevent UAF in proc_cpuset_show() An UAF can happen when /proc/cpuset is read as reported in [1]. This can be reproduced by the following methods: 1.add an mdelay(1000) before acquiring the cgroup_lock In the cgroup_path_ns function. 2.$cat /proc/<pid>/cpuset repeatly. 3.$mount -t cgroup -o cpuset cpuset /sys/fs/cgroup/cpuset/ $umount /sys/fs/cgroup/cpuset/ repeatly. The race that cause this bug can be sh ... In the Linux kernel, the following vulnerability has been resolved: cgroup/cpuset: Prevent UAF in proc_cpuset_show() An UAF can happen when /proc/cpuset is read as reported in [1]. This can be reproduced by the following methods: 1.add an mdelay(1000) before acquiring the cgroup_lock In the cgroup_path_ns function. 2.$cat /proc/<pid>/cpuset repeatly. 3.$mount -t cgroup -o cpuset cpuset /sys/fs/cgroup/cpuset/ $umount /sys/fs/cgroup/cpuset/ repeatly. The race that cause this bug can be shown as below: (umount) | (cat /proc/<pid>/cpuset) css_release | proc_cpuset_show css_release_work_fn | css = task_get_css(tsk, cpuset_cgrp_id); css_free_rwork_fn | cgroup_path_ns(css->cgroup, ...); cgroup_destroy_root | mutex_lock(&cgroup_mutex); rebind_subsystems | cgroup_free_root | | // cgrp was freed, UAF | cgroup_path_ns_locked(cgrp,..); When the cpuset is initialized, the root node top_cpuset.css.cgrp will point to &cgrp_dfl_root.cgrp. In cgroup v1, the mount operation will allocate cgroup_root, and top_cpuset.css.cgrp will point to the allocated &cgroup_root.cgrp. When the umount operation is executed, top_cpuset.css.cgrp will be rebound to &cgrp_dfl_root.cgrp. The problem is that when rebinding to cgrp_dfl_root, there are cases where the cgroup_root allocated by setting up the root for cgroup v1 is cached. This could lead to a Use-After-Free (UAF) if it is subsequently freed. The descendant cgroups of cgroup v1 can only be freed after the css is released. However, the css of the root will never be released, yet the cgroup_root should be freed when it is unmounted. This means that obtaining a reference to the css of the root does not guarantee that css.cgrp->root will not be freed. Fix this problem by using rcu_read_lock in proc_cpuset_show(). As cgroup_root is kfree_rcu after commit d23b5c577715 ("cgroup: Make operations on the cgroup root_list RCU safe"), css->cgroup won't be freed during the critical section. To call cgroup_path_ns_locked, css_set_lock is needed, so it is safe to replace task_get_css with task_css. [1] https://syzkaller.appspot.com/bug?extid=9b1ff7be974a403aa4cd

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