Linux: >> Linux Kernel >> 2.6.15.6 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
rcu: Fix rcu_read_unlock() deadloop due to IRQ work
During rcu_read_unlock_special(), if this happens during irq_exit(), we
can lockup if an IPI is issued. This is because the IPI itself triggers
the irq_exit() path causing a recursive lock up.
This is precisely what Xiongfeng found when invoking a BPF program on
the trace_tick_stop() tracepoint As shown in the trace below. Fix by
managing the irq_work state correctly.
irq_exit()
__irq_exit_rcu()
/* in_hardirq() returns false after this */
preempt_count_sub(HARDIRQ_OFFSET)
tick_irq_exit()
tick_nohz_irq_exit()
tick_nohz_stop_sched_tick()
trace_tick_stop() /* a bpf prog is hooked on this trace point */
__bpf_trace_tick_stop()
bpf_trace_run2()
rcu_read_unlock_special()
/* will send a IPI to itself */
irq_work_queue_on(&rdp->defer_qs_iw, rdp->cpu);
A simple reproducer can also be obtained by doing the following in
tick_irq_exit(). It will hang on boot without the patch:
static inline void tick_irq_exit(void)
{
+ rcu_read_lock();
+ WRITE_ONCE(current->rcu_read_unlock_special.b.need_qs, true);
+ rcu_read_unlock();
+
[neeraj: Apply Frederic's suggested fix for PREEMPT_RT]
CVSS Score
7.1
EPSS Score
0.0
Published
2025-09-11
In the Linux kernel, the following vulnerability has been resolved:
rcutorture: Fix rcutorture_one_extend_check() splat in RT kernels
For built with CONFIG_PREEMPT_RT=y kernels, running rcutorture
tests resulted in the following splat:
[ 68.797425] rcutorture_one_extend_check during change: Current 0x1 To add 0x1 To remove 0x0 preempt_count() 0x0
[ 68.797533] WARNING: CPU: 2 PID: 512 at kernel/rcu/rcutorture.c:1993 rcutorture_one_extend_check+0x419/0x560 [rcutorture]
[ 68.797601] Call Trace:
[ 68.797602] <TASK>
[ 68.797619] ? lockdep_softirqs_off+0xa5/0x160
[ 68.797631] rcutorture_one_extend+0x18e/0xcc0 [rcutorture 2466dbd2ff34dbaa36049cb323a80c3306ac997c]
[ 68.797646] ? local_clock+0x19/0x40
[ 68.797659] rcu_torture_one_read+0xf0/0x280 [rcutorture 2466dbd2ff34dbaa36049cb323a80c3306ac997c]
[ 68.797678] ? __pfx_rcu_torture_one_read+0x10/0x10 [rcutorture 2466dbd2ff34dbaa36049cb323a80c3306ac997c]
[ 68.797804] ? __pfx_rcu_torture_timer+0x10/0x10 [rcutorture 2466dbd2ff34dbaa36049cb323a80c3306ac997c]
[ 68.797815] rcu-torture: rcu_torture_reader task started
[ 68.797824] rcu-torture: Creating rcu_torture_reader task
[ 68.797824] rcu_torture_reader+0x238/0x580 [rcutorture 2466dbd2ff34dbaa36049cb323a80c3306ac997c]
[ 68.797836] ? kvm_sched_clock_read+0x15/0x30
Disable BH does not change the SOFTIRQ corresponding bits in
preempt_count() for RT kernels, this commit therefore use
softirq_count() to check the if BH is disabled.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-11
In the Linux kernel, the following vulnerability has been resolved:
hfs: fix general protection fault in hfs_find_init()
The hfs_find_init() method can trigger the crash
if tree pointer is NULL:
[ 45.746290][ T9787] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] SMP KAI
[ 45.747287][ T9787] KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047]
[ 45.748716][ T9787] CPU: 2 UID: 0 PID: 9787 Comm: repro Not tainted 6.16.0-rc3 #10 PREEMPT(full)
[ 45.750250][ T9787] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 45.751983][ T9787] RIP: 0010:hfs_find_init+0x86/0x230
[ 45.752834][ T9787] Code: c1 ea 03 80 3c 02 00 0f 85 9a 01 00 00 4c 8d 6b 40 48 c7 45 18 00 00 00 00 48 b8 00 00 00 00 00 fc
[ 45.755574][ T9787] RSP: 0018:ffffc90015157668 EFLAGS: 00010202
[ 45.756432][ T9787] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff819a4d09
[ 45.757457][ T9787] RDX: 0000000000000008 RSI: ffffffff819acd3a RDI: ffffc900151576e8
[ 45.758282][ T9787] RBP: ffffc900151576d0 R08: 0000000000000005 R09: 0000000000000000
[ 45.758943][ T9787] R10: 0000000080000000 R11: 0000000000000001 R12: 0000000000000004
[ 45.759619][ T9787] R13: 0000000000000040 R14: ffff88802c50814a R15: 0000000000000000
[ 45.760293][ T9787] FS: 00007ffb72734540(0000) GS:ffff8880cec64000(0000) knlGS:0000000000000000
[ 45.761050][ T9787] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 45.761606][ T9787] CR2: 00007f9bd8225000 CR3: 000000010979a000 CR4: 00000000000006f0
[ 45.762286][ T9787] Call Trace:
[ 45.762570][ T9787] <TASK>
[ 45.762824][ T9787] hfs_ext_read_extent+0x190/0x9d0
[ 45.763269][ T9787] ? submit_bio_noacct_nocheck+0x2dd/0xce0
[ 45.763766][ T9787] ? __pfx_hfs_ext_read_extent+0x10/0x10
[ 45.764250][ T9787] hfs_get_block+0x55f/0x830
[ 45.764646][ T9787] block_read_full_folio+0x36d/0x850
[ 45.765105][ T9787] ? __pfx_hfs_get_block+0x10/0x10
[ 45.765541][ T9787] ? const_folio_flags+0x5b/0x100
[ 45.765972][ T9787] ? __pfx_hfs_read_folio+0x10/0x10
[ 45.766415][ T9787] filemap_read_folio+0xbe/0x290
[ 45.766840][ T9787] ? __pfx_filemap_read_folio+0x10/0x10
[ 45.767325][ T9787] ? __filemap_get_folio+0x32b/0xbf0
[ 45.767780][ T9787] do_read_cache_folio+0x263/0x5c0
[ 45.768223][ T9787] ? __pfx_hfs_read_folio+0x10/0x10
[ 45.768666][ T9787] read_cache_page+0x5b/0x160
[ 45.769070][ T9787] hfs_btree_open+0x491/0x1740
[ 45.769481][ T9787] hfs_mdb_get+0x15e2/0x1fb0
[ 45.769877][ T9787] ? __pfx_hfs_mdb_get+0x10/0x10
[ 45.770316][ T9787] ? find_held_lock+0x2b/0x80
[ 45.770731][ T9787] ? lockdep_init_map_type+0x5c/0x280
[ 45.771200][ T9787] ? lockdep_init_map_type+0x5c/0x280
[ 45.771674][ T9787] hfs_fill_super+0x38e/0x720
[ 45.772092][ T9787] ? __pfx_hfs_fill_super+0x10/0x10
[ 45.772549][ T9787] ? snprintf+0xbe/0x100
[ 45.772931][ T9787] ? __pfx_snprintf+0x10/0x10
[ 45.773350][ T9787] ? do_raw_spin_lock+0x129/0x2b0
[ 45.773796][ T9787] ? find_held_lock+0x2b/0x80
[ 45.774215][ T9787] ? set_blocksize+0x40a/0x510
[ 45.774636][ T9787] ? sb_set_blocksize+0x176/0x1d0
[ 45.775087][ T9787] ? setup_bdev_super+0x369/0x730
[ 45.775533][ T9787] get_tree_bdev_flags+0x384/0x620
[ 45.775985][ T9787] ? __pfx_hfs_fill_super+0x10/0x10
[ 45.776453][ T9787] ? __pfx_get_tree_bdev_flags+0x10/0x10
[ 45.776950][ T9787] ? bpf_lsm_capable+0x9/0x10
[ 45.777365][ T9787] ? security_capable+0x80/0x260
[ 45.777803][ T9787] vfs_get_tree+0x8e/0x340
[ 45.778203][ T9787] path_mount+0x13de/0x2010
[ 45.778604][ T9787] ? kmem_cache_free+0x2b0/0x4c0
[ 45.779052][ T9787] ? __pfx_path_mount+0x10/0x10
[ 45.779480][ T9787] ? getname_flags.part.0+0x1c5/0x550
[ 45.779954][ T9787] ? putname+0x154/0x1a0
[ 45.780335][ T9787] __x64_sys_mount+0x27b/0x300
[ 45.780758][ T9787] ? __pfx___x64_sys_mount+0x10/0x10
[ 45.781232][ T9787]
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-04
In the Linux kernel, the following vulnerability has been resolved:
gfs2: Validate i_depth for exhash directories
A fuzzer test introduced corruption that ends up with a depth of 0 in
dir_e_read(), causing an undefined shift by 32 at:
index = hash >> (32 - dip->i_depth);
As calculated in an open-coded way in dir_make_exhash(), the minimum
depth for an exhash directory is ilog2(sdp->sd_hash_ptrs) and 0 is
invalid as sdp->sd_hash_ptrs is fixed as sdp->bsize / 16 at mount time.
So we can avoid the undefined behaviour by checking for depth values
lower than the minimum in gfs2_dinode_in(). Values greater than the
maximum are already being checked for there.
Also switch the calculation in dir_make_exhash() to use ilog2() to
clarify how the depth is calculated.
Tested with the syzkaller repro.c and xfstests '-g quick'.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-04
In the Linux kernel, the following vulnerability has been resolved:
rcu/nocb: Fix possible invalid rdp's->nocb_cb_kthread pointer access
In the preparation stage of CPU online, if the corresponding
the rdp's->nocb_cb_kthread does not exist, will be created,
there is a situation where the rdp's rcuop kthreads creation fails,
and then de-offload this CPU's rdp, does not assign this CPU's
rdp->nocb_cb_kthread pointer, but this rdp's->nocb_gp_rdp and
rdp's->rdp_gp->nocb_gp_kthread is still valid.
This will cause the subsequent re-offload operation of this offline
CPU, which will pass the conditional check and the kthread_unpark()
will access invalid rdp's->nocb_cb_kthread pointer.
This commit therefore use rdp's->nocb_gp_kthread instead of
rdp_gp's->nocb_gp_kthread for safety check.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-09-04
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/pm: fix null pointer access
Writing a string without delimiters (' ', '\n', '\0') to the under
gpu_od/fan_ctrl sysfs or pp_power_profile_mode for the CUSTOM profile
will result in a null pointer dereference.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-04
In the Linux kernel, the following vulnerability has been resolved:
loop: Avoid updating block size under exclusive owner
Syzbot came up with a reproducer where a loop device block size is
changed underneath a mounted filesystem. This causes a mismatch between
the block device block size and the block size stored in the superblock
causing confusion in various places such as fs/buffer.c. The particular
issue triggered by syzbot was a warning in __getblk_slow() due to
requested buffer size not matching block device block size.
Fix the problem by getting exclusive hold of the loop device to change
its block size. This fails if somebody (such as filesystem) has already
an exclusive ownership of the block device and thus prevents modifying
the loop device under some exclusive owner which doesn't expect it.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-04
In the Linux kernel, the following vulnerability has been resolved:
iio: common: st_sensors: Fix use of uninitialize device structs
Throughout the various probe functions &indio_dev->dev is used before it
is initialized. This caused a kernel panic in st_sensors_power_enable()
when the call to devm_regulator_bulk_get_enable() fails and then calls
dev_err_probe() with the uninitialized device.
This seems to only cause a panic with dev_err_probe(), dev_err(),
dev_warn() and dev_info() don't seem to cause a panic, but are fixed
as well.
The issue is reported and traced here: [1]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-08-16
In the Linux kernel, the following vulnerability has been resolved:
netlink: Fix wraparounds of sk->sk_rmem_alloc.
Netlink has this pattern in some places
if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf)
atomic_add(skb->truesize, &sk->sk_rmem_alloc);
, which has the same problem fixed by commit 5a465a0da13e ("udp:
Fix multiple wraparounds of sk->sk_rmem_alloc.").
For example, if we set INT_MAX to SO_RCVBUFFORCE, the condition
is always false as the two operands are of int.
Then, a single socket can eat as many skb as possible until OOM
happens, and we can see multiple wraparounds of sk->sk_rmem_alloc.
Let's fix it by using atomic_add_return() and comparing the two
variables as unsigned int.
Before:
[root@fedora ~]# ss -f netlink
Recv-Q Send-Q Local Address:Port Peer Address:Port
-1668710080 0 rtnl:nl_wraparound/293 *
After:
[root@fedora ~]# ss -f netlink
Recv-Q Send-Q Local Address:Port Peer Address:Port
2147483072 0 rtnl:nl_wraparound/290 *
^
`--- INT_MAX - 576
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-25
In the Linux kernel, the following vulnerability has been resolved:
atm: clip: Fix NULL pointer dereference in vcc_sendmsg()
atmarpd_dev_ops does not implement the send method, which may cause crash
as bellow.
BUG: kernel NULL pointer dereference, address: 0000000000000000
PGD 0 P4D 0
Oops: Oops: 0010 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5324 Comm: syz.0.0 Not tainted 6.15.0-rc6-syzkaller-00346-g5723cc3450bc #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc9000d3cf778 EFLAGS: 00010246
RAX: 1ffffffff1910dd1 RBX: 00000000000000c0 RCX: dffffc0000000000
RDX: ffffc9000dc82000 RSI: ffff88803e4c4640 RDI: ffff888052cd0000
RBP: ffffc9000d3cf8d0 R08: ffff888052c9143f R09: 1ffff1100a592287
R10: dffffc0000000000 R11: 0000000000000000 R12: 1ffff92001a79f00
R13: ffff888052cd0000 R14: ffff88803e4c4640 R15: ffffffff8c886e88
FS: 00007fbc762566c0(0000) GS:ffff88808d6c2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000041f1b000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
vcc_sendmsg+0xa10/0xc50 net/atm/common.c:644
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x219/0x270 net/socket.c:727
____sys_sendmsg+0x52d/0x830 net/socket.c:2566
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620
__sys_sendmmsg+0x227/0x430 net/socket.c:2709
__do_sys_sendmmsg net/socket.c:2736 [inline]
__se_sys_sendmmsg net/socket.c:2733 [inline]
__x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2733
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-25