Linux: >> Linux Kernel >> 4.20.10 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
btrfs: insert tree mod log move in push_node_left
There is a fairly unlikely race condition in tree mod log rewind that
can result in a kernel panic which has the following trace:
[530.569] BTRFS critical (device sda3): unable to find logical 0 length 4096
[530.585] BTRFS critical (device sda3): unable to find logical 0 length 4096
[530.602] BUG: kernel NULL pointer dereference, address: 0000000000000002
[530.618] #PF: supervisor read access in kernel mode
[530.629] #PF: error_code(0x0000) - not-present page
[530.641] PGD 0 P4D 0
[530.647] Oops: 0000 [#1] SMP
[530.654] CPU: 30 PID: 398973 Comm: below Kdump: loaded Tainted: G S O K 5.12.0-0_fbk13_clang_7455_gb24de3bdb045 #1
[530.680] Hardware name: Quanta Mono Lake-M.2 SATA 1HY9U9Z001G/Mono Lake-M.2 SATA, BIOS F20_3A15 08/16/2017
[530.703] RIP: 0010:__btrfs_map_block+0xaa/0xd00
[530.755] RSP: 0018:ffffc9002c2f7600 EFLAGS: 00010246
[530.767] RAX: ffffffffffffffea RBX: ffff888292e41000 RCX: f2702d8b8be15100
[530.784] RDX: ffff88885fda6fb8 RSI: ffff88885fd973c8 RDI: ffff88885fd973c8
[530.800] RBP: ffff888292e410d0 R08: ffffffff82fd7fd0 R09: 00000000fffeffff
[530.816] R10: ffffffff82e57fd0 R11: ffffffff82e57d70 R12: 0000000000000000
[530.832] R13: 0000000000001000 R14: 0000000000001000 R15: ffffc9002c2f76f0
[530.848] FS: 00007f38d64af000(0000) GS:ffff88885fd80000(0000) knlGS:0000000000000000
[530.866] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[530.880] CR2: 0000000000000002 CR3: 00000002b6770004 CR4: 00000000003706e0
[530.896] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[530.912] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[530.928] Call Trace:
[530.934] ? btrfs_printk+0x13b/0x18c
[530.943] ? btrfs_bio_counter_inc_blocked+0x3d/0x130
[530.955] btrfs_map_bio+0x75/0x330
[530.963] ? kmem_cache_alloc+0x12a/0x2d0
[530.973] ? btrfs_submit_metadata_bio+0x63/0x100
[530.984] btrfs_submit_metadata_bio+0xa4/0x100
[530.995] submit_extent_page+0x30f/0x360
[531.004] read_extent_buffer_pages+0x49e/0x6d0
[531.015] ? submit_extent_page+0x360/0x360
[531.025] btree_read_extent_buffer_pages+0x5f/0x150
[531.037] read_tree_block+0x37/0x60
[531.046] read_block_for_search+0x18b/0x410
[531.056] btrfs_search_old_slot+0x198/0x2f0
[531.066] resolve_indirect_ref+0xfe/0x6f0
[531.076] ? ulist_alloc+0x31/0x60
[531.084] ? kmem_cache_alloc_trace+0x12e/0x2b0
[531.095] find_parent_nodes+0x720/0x1830
[531.105] ? ulist_alloc+0x10/0x60
[531.113] iterate_extent_inodes+0xea/0x370
[531.123] ? btrfs_previous_extent_item+0x8f/0x110
[531.134] ? btrfs_search_path_in_tree+0x240/0x240
[531.146] iterate_inodes_from_logical+0x98/0xd0
[531.157] ? btrfs_search_path_in_tree+0x240/0x240
[531.168] btrfs_ioctl_logical_to_ino+0xd9/0x180
[531.179] btrfs_ioctl+0xe2/0x2eb0
This occurs when logical inode resolution takes a tree mod log sequence
number, and then while backref walking hits a rewind on a busy node
which has the following sequence of tree mod log operations (numbers
filled in from a specific example, but they are somewhat arbitrary)
REMOVE_WHILE_FREEING slot 532
REMOVE_WHILE_FREEING slot 531
REMOVE_WHILE_FREEING slot 530
...
REMOVE_WHILE_FREEING slot 0
REMOVE slot 455
REMOVE slot 454
REMOVE slot 453
...
REMOVE slot 0
ADD slot 455
ADD slot 454
ADD slot 453
...
ADD slot 0
MOVE src slot 0 -> dst slot 456 nritems 533
REMOVE slot 455
REMOVE slot 454
REMOVE slot 453
...
REMOVE slot 0
When this sequence gets applied via btrfs_tree_mod_log_rewind, it
allocates a fresh rewind eb, and first inserts the correct key info for
the 533 elements, then overwrites the first 456 of them, then decrements
the count by 456 via the add ops, then rewinds the move by doing a
memmove from 456:988->0:532. We have never written anything past 532,
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: Fix incomplete state save in rxe_requester
If a send packet is dropped by the IP layer in rxe_requester()
the call to rxe_xmit_packet() can fail with err == -EAGAIN.
To recover, the state of the wqe is restored to the state before
the packet was sent so it can be resent. However, the routines
that save and restore the state miss a significnt part of the
variable state in the wqe, the dma struct which is used to process
through the sge table. And, the state is not saved before the packet
is built which modifies the dma struct.
Under heavy stress testing with many QPs on a fast node sending
large messages to a slow node dropped packets are observed and
the resent packets are corrupted because the dma struct was not
restored. This patch fixes this behavior and allows the test cases
to succeed.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
netdevsim: fix memory leak in nsim_drv_probe() when nsim_dev_resources_register() failed
If some items in nsim_dev_resources_register() fail, memory leak will
occur. The following is the memory leak information.
unreferenced object 0xffff888074c02600 (size 128):
comm "echo", pid 8159, jiffies 4294945184 (age 493.530s)
hex dump (first 32 bytes):
40 47 ea 89 ff ff ff ff 01 00 00 00 00 00 00 00 @G..............
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
backtrace:
[<0000000011a31c98>] kmalloc_trace+0x22/0x60
[<0000000027384c69>] devl_resource_register+0x144/0x4e0
[<00000000a16db248>] nsim_drv_probe+0x37a/0x1260
[<000000007d1f448c>] really_probe+0x20b/0xb10
[<00000000c416848a>] __driver_probe_device+0x1b3/0x4a0
[<00000000077e0351>] driver_probe_device+0x49/0x140
[<0000000054f2465a>] __device_attach_driver+0x18c/0x2a0
[<000000008538f359>] bus_for_each_drv+0x151/0x1d0
[<0000000038e09747>] __device_attach+0x1c9/0x4e0
[<00000000dd86e533>] bus_probe_device+0x1d5/0x280
[<00000000839bea35>] device_add+0xae0/0x1cb0
[<000000009c2abf46>] new_device_store+0x3b6/0x5f0
[<00000000fb823d7f>] bus_attr_store+0x72/0xa0
[<000000007acc4295>] sysfs_kf_write+0x106/0x160
[<000000005f50cb4d>] kernfs_fop_write_iter+0x3a8/0x5a0
[<0000000075eb41bf>] vfs_write+0x8f0/0xc80
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
media: coda: Add check for dcoda_iram_alloc
As the coda_iram_alloc may return NULL pointer,
it should be better to check the return value
in order to avoid NULL poineter dereference,
same as the others.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
mtd: lpddr2_nvm: Fix possible null-ptr-deref
It will cause null-ptr-deref when resource_size(add_range) invoked,
if platform_get_resource() returns NULL.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
powerpc/rtas: avoid scheduling in rtas_os_term()
It's unsafe to use rtas_busy_delay() to handle a busy status from
the ibm,os-term RTAS function in rtas_os_term():
Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
BUG: sleeping function called from invalid context at arch/powerpc/kernel/rtas.c:618
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 1, name: swapper/0
preempt_count: 2, expected: 0
CPU: 7 PID: 1 Comm: swapper/0 Tainted: G D 6.0.0-rc5-02182-gf8553a572277-dirty #9
Call Trace:
[c000000007b8f000] [c000000001337110] dump_stack_lvl+0xb4/0x110 (unreliable)
[c000000007b8f040] [c0000000002440e4] __might_resched+0x394/0x3c0
[c000000007b8f0e0] [c00000000004f680] rtas_busy_delay+0x120/0x1b0
[c000000007b8f100] [c000000000052d04] rtas_os_term+0xb8/0xf4
[c000000007b8f180] [c0000000001150fc] pseries_panic+0x50/0x68
[c000000007b8f1f0] [c000000000036354] ppc_panic_platform_handler+0x34/0x50
[c000000007b8f210] [c0000000002303c4] notifier_call_chain+0xd4/0x1c0
[c000000007b8f2b0] [c0000000002306cc] atomic_notifier_call_chain+0xac/0x1c0
[c000000007b8f2f0] [c0000000001d62b8] panic+0x228/0x4d0
[c000000007b8f390] [c0000000001e573c] do_exit+0x140c/0x1420
[c000000007b8f480] [c0000000001e586c] make_task_dead+0xdc/0x200
Use rtas_busy_delay_time() instead, which signals without side effects
whether to attempt the ibm,os-term RTAS call again.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
iommu/amd: Fix pci device refcount leak in ppr_notifier()
As comment of pci_get_domain_bus_and_slot() says, it returns
a pci device with refcount increment, when finish using it,
the caller must decrement the reference count by calling
pci_dev_put(). So call it before returning from ppr_notifier()
to avoid refcount leak.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
drm/msm: fix use-after-free on probe deferral
The bridge counter was never reset when tearing down the DRM device so
that stale pointers to deallocated structures would be accessed on the
next tear down (e.g. after a second late bind deferral).
Given enough bridges and a few probe deferrals this could currently also
lead to data beyond the bridge array being corrupted.
Patchwork: https://patchwork.freedesktop.org/patch/502665/
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
thermal: intel_powerclamp: Use get_cpu() instead of smp_processor_id() to avoid crash
When CPU 0 is offline and intel_powerclamp is used to inject
idle, it generates kernel BUG:
BUG: using smp_processor_id() in preemptible [00000000] code: bash/15687
caller is debug_smp_processor_id+0x17/0x20
CPU: 4 PID: 15687 Comm: bash Not tainted 5.19.0-rc7+ #57
Call Trace:
<TASK>
dump_stack_lvl+0x49/0x63
dump_stack+0x10/0x16
check_preemption_disabled+0xdd/0xe0
debug_smp_processor_id+0x17/0x20
powerclamp_set_cur_state+0x7f/0xf9 [intel_powerclamp]
...
...
Here CPU 0 is the control CPU by default and changed to the current CPU,
if CPU 0 offlined. This check has to be performed under cpus_read_lock(),
hence the above warning.
Use get_cpu() instead of smp_processor_id() to avoid this BUG.
[ rjw: Subject edits ]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
dm cache: Fix UAF in destroy()
Dm_cache also has the same UAF problem when dm_resume()
and dm_destroy() are concurrent.
Therefore, cancelling timer again in destroy().
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-04