Linux: >> Linux Kernel >> 4.12.10 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
btrfs: correct the order of prelim_ref arguments in btrfs__prelim_ref
btrfs_prelim_ref() calls the old and new reference variables in the
incorrect order. This causes a NULL pointer dereference because oldref
is passed as NULL to trace_btrfs_prelim_ref_insert().
Note, trace_btrfs_prelim_ref_insert() is being called with newref as
oldref (and oldref as NULL) on purpose in order to print out
the values of newref.
To reproduce:
echo 1 > /sys/kernel/debug/tracing/events/btrfs/btrfs_prelim_ref_insert/enable
Perform some writeback operations.
Backtrace:
BUG: kernel NULL pointer dereference, address: 0000000000000018
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 115949067 P4D 115949067 PUD 11594a067 PMD 0
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 1 UID: 0 PID: 1188 Comm: fsstress Not tainted 6.15.0-rc2-tester+ #47 PREEMPT(voluntary) 7ca2cef72d5e9c600f0c7718adb6462de8149622
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-2-gc13ff2cd-prebuilt.qemu.org 04/01/2014
RIP: 0010:trace_event_raw_event_btrfs__prelim_ref+0x72/0x130
Code: e8 43 81 9f ff 48 85 c0 74 78 4d 85 e4 0f 84 8f 00 00 00 49 8b 94 24 c0 06 00 00 48 8b 0a 48 89 48 08 48 8b 52 08 48 89 50 10 <49> 8b 55 18 48 89 50 18 49 8b 55 20 48 89 50 20 41 0f b6 55 28 88
RSP: 0018:ffffce44820077a0 EFLAGS: 00010286
RAX: ffff8c6b403f9014 RBX: ffff8c6b55825730 RCX: 304994edf9cf506b
RDX: d8b11eb7f0fdb699 RSI: ffff8c6b403f9010 RDI: ffff8c6b403f9010
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000010
R10: 00000000ffffffff R11: 0000000000000000 R12: ffff8c6b4e8fb000
R13: 0000000000000000 R14: ffffce44820077a8 R15: ffff8c6b4abd1540
FS: 00007f4dc6813740(0000) GS:ffff8c6c1d378000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000018 CR3: 000000010eb42000 CR4: 0000000000750ef0
PKRU: 55555554
Call Trace:
<TASK>
prelim_ref_insert+0x1c1/0x270
find_parent_nodes+0x12a6/0x1ee0
? __entry_text_end+0x101f06/0x101f09
? srso_alias_return_thunk+0x5/0xfbef5
? srso_alias_return_thunk+0x5/0xfbef5
? srso_alias_return_thunk+0x5/0xfbef5
? srso_alias_return_thunk+0x5/0xfbef5
btrfs_is_data_extent_shared+0x167/0x640
? fiemap_process_hole+0xd0/0x2c0
extent_fiemap+0xa5c/0xbc0
? __entry_text_end+0x101f05/0x101f09
btrfs_fiemap+0x7e/0xd0
do_vfs_ioctl+0x425/0x9d0
__x64_sys_ioctl+0x75/0xc0
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
nfs: handle failure of nfs_get_lock_context in unlock path
When memory is insufficient, the allocation of nfs_lock_context in
nfs_get_lock_context() fails and returns -ENOMEM. If we mistakenly treat
an nfs4_unlockdata structure (whose l_ctx member has been set to -ENOMEM)
as valid and proceed to execute rpc_run_task(), this will trigger a NULL
pointer dereference in nfs4_locku_prepare. For example:
BUG: kernel NULL pointer dereference, address: 000000000000000c
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP PTI
CPU: 15 UID: 0 PID: 12 Comm: kworker/u64:0 Not tainted 6.15.0-rc2-dirty #60
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40
Workqueue: rpciod rpc_async_schedule
RIP: 0010:nfs4_locku_prepare+0x35/0xc2
Code: 89 f2 48 89 fd 48 c7 c7 68 69 ef b5 53 48 8b 8e 90 00 00 00 48 89 f3
RSP: 0018:ffffbbafc006bdb8 EFLAGS: 00010246
RAX: 000000000000004b RBX: ffff9b964fc1fa00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: fffffffffffffff4 RDI: ffff9ba53fddbf40
RBP: ffff9ba539934000 R08: 0000000000000000 R09: ffffbbafc006bc38
R10: ffffffffb6b689c8 R11: 0000000000000003 R12: ffff9ba539934030
R13: 0000000000000001 R14: 0000000004248060 R15: ffffffffb56d1c30
FS: 0000000000000000(0000) GS:ffff9ba5881f0000(0000) knlGS:00000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000000c CR3: 000000093f244000 CR4: 00000000000006f0
Call Trace:
<TASK>
__rpc_execute+0xbc/0x480
rpc_async_schedule+0x2f/0x40
process_one_work+0x232/0x5d0
worker_thread+0x1da/0x3d0
? __pfx_worker_thread+0x10/0x10
kthread+0x10d/0x240
? __pfx_kthread+0x10/0x10
ret_from_fork+0x34/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Modules linked in:
CR2: 000000000000000c
---[ end trace 0000000000000000 ]---
Free the allocated nfs4_unlockdata when nfs_get_lock_context() fails and
return NULL to terminate subsequent rpc_run_task, preventing NULL pointer
dereference.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: Fix slab-use-after-free Read in rxe_queue_cleanup bug
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x7d/0xa0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xcf/0x610 mm/kasan/report.c:489
kasan_report+0xb5/0xe0 mm/kasan/report.c:602
rxe_queue_cleanup+0xd0/0xe0 drivers/infiniband/sw/rxe/rxe_queue.c:195
rxe_cq_cleanup+0x3f/0x50 drivers/infiniband/sw/rxe/rxe_cq.c:132
__rxe_cleanup+0x168/0x300 drivers/infiniband/sw/rxe/rxe_pool.c:232
rxe_create_cq+0x22e/0x3a0 drivers/infiniband/sw/rxe/rxe_verbs.c:1109
create_cq+0x658/0xb90 drivers/infiniband/core/uverbs_cmd.c:1052
ib_uverbs_create_cq+0xc7/0x120 drivers/infiniband/core/uverbs_cmd.c:1095
ib_uverbs_write+0x969/0xc90 drivers/infiniband/core/uverbs_main.c:679
vfs_write fs/read_write.c:677 [inline]
vfs_write+0x26a/0xcc0 fs/read_write.c:659
ksys_write+0x1b8/0x200 fs/read_write.c:731
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xaa/0x1b0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
In the function rxe_create_cq, when rxe_cq_from_init fails, the function
rxe_cleanup will be called to handle the allocated resources. In fact,
some memory resources have already been freed in the function
rxe_cq_from_init. Thus, this problem will occur.
The solution is to let rxe_cleanup do all the work.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
can: bcm: add locking for bcm_op runtime updates
The CAN broadcast manager (CAN BCM) can send a sequence of CAN frames via
hrtimer. The content and also the length of the sequence can be changed
resp reduced at runtime where the 'currframe' counter is then set to zero.
Although this appeared to be a safe operation the updates of 'currframe'
can be triggered from user space and hrtimer context in bcm_can_tx().
Anderson Nascimento created a proof of concept that triggered a KASAN
slab-out-of-bounds read access which can be prevented with a spin_lock_bh.
At the rework of bcm_can_tx() the 'count' variable has been moved into
the protected section as this variable can be modified from both contexts
too.
CVSS Score
7.1
EPSS Score
0.0
Published
2025-06-08
In the Linux kernel, the following vulnerability has been resolved:
sch_hfsc: Fix qlen accounting bug when using peek in hfsc_enqueue()
When enqueuing the first packet to an HFSC class, hfsc_enqueue() calls the
child qdisc's peek() operation before incrementing sch->q.qlen and
sch->qstats.backlog. If the child qdisc uses qdisc_peek_dequeued(), this may
trigger an immediate dequeue and potential packet drop. In such cases,
qdisc_tree_reduce_backlog() is called, but the HFSC qdisc's qlen and backlog
have not yet been updated, leading to inconsistent queue accounting. This
can leave an empty HFSC class in the active list, causing further
consequences like use-after-free.
This patch fixes the bug by moving the increment of sch->q.qlen and
sch->qstats.backlog before the call to the child qdisc's peek() operation.
This ensures that queue length and backlog are always accurate when packet
drops or dequeues are triggered during the peek.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-06-06
A vulnerability was found in systemd-coredump. This flaw allows an attacker to force a SUID process to crash and replace it with a non-SUID binary to access the original's privileged process coredump, allowing the attacker to read sensitive data, such as /etc/shadow content, loaded by the original process.
A SUID binary or process has a special type of permission, which allows the process to run with the file owner's permissions, regardless of the user executing the binary. This allows the process to access more restricted data than unprivileged users or processes would be able to. An attacker can leverage this flaw by forcing a SUID process to crash and force the Linux kernel to recycle the process PID before systemd-coredump can analyze the /proc/pid/auxv file. If the attacker wins the race condition, they gain access to the original's SUID process coredump file. They can read sensitive content loaded into memory by the original binary, affecting data confidentiality.
CVSS Score
4.7
EPSS Score
0.0
Published
2025-05-30
In the Linux kernel, the following vulnerability has been resolved:
module: ensure that kobject_put() is safe for module type kobjects
In 'lookup_or_create_module_kobject()', an internal kobject is created
using 'module_ktype'. So call to 'kobject_put()' on error handling
path causes an attempt to use an uninitialized completion pointer in
'module_kobject_release()'. In this scenario, we just want to release
kobject without an extra synchronization required for a regular module
unloading process, so adding an extra check whether 'complete()' is
actually required makes 'kobject_put()' safe.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-29
In the Linux kernel, the following vulnerability has been resolved:
openvswitch: Fix unsafe attribute parsing in output_userspace()
This patch replaces the manual Netlink attribute iteration in
output_userspace() with nla_for_each_nested(), which ensures that only
well-formed attributes are processed.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-29
In the Linux kernel, the following vulnerability has been resolved:
net_sched: Flush gso_skb list too during ->change()
Previously, when reducing a qdisc's limit via the ->change() operation, only
the main skb queue was trimmed, potentially leaving packets in the gso_skb
list. This could result in NULL pointer dereference when we only check
sch->limit against sch->q.qlen.
This patch introduces a new helper, qdisc_dequeue_internal(), which ensures
both the gso_skb list and the main queue are properly flushed when trimming
excess packets. All relevant qdiscs (codel, fq, fq_codel, fq_pie, hhf, pie)
are updated to use this helper in their ->change() routines.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-26
In the Linux kernel, the following vulnerability has been resolved:
qibfs: fix _another_ leak
failure to allocate inode => leaked dentry...
this one had been there since the initial merge; to be fair,
if we are that far OOM, the odds of failing at that particular
allocation are low...
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-20