Linux: >> Linux Kernel >> 4.2.1 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
udf: Do not bother merging very long extents
When merging very long extents we try to push as much length as possible
to the first extent. However this is unnecessarily complicated and not
really worth the trouble. Furthermore there was a bug in the logic
resulting in corrupting extents in the file as syzbot reproducer shows.
So just don't bother with the merging of extents that are too long
together.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: core: Fix handling of lrbp->cmd
ufshcd_queuecommand() may be called two times in a row for a SCSI command
before it is completed. Hence make the following changes:
- In the functions that submit a command, do not check the old value of
lrbp->cmd nor clear lrbp->cmd in error paths.
- In ufshcd_release_scsi_cmd(), do not clear lrbp->cmd.
See also scsi_send_eh_cmnd().
This commit prevents that the following appears if a command times out:
WARNING: at drivers/ufs/core/ufshcd.c:2965 ufshcd_queuecommand+0x6f8/0x9a8
Call trace:
ufshcd_queuecommand+0x6f8/0x9a8
scsi_send_eh_cmnd+0x2c0/0x960
scsi_eh_test_devices+0x100/0x314
scsi_eh_ready_devs+0xd90/0x114c
scsi_error_handler+0x2b4/0xb70
kthread+0x16c/0x1e0
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
xfrm: fix slab-use-after-free in decode_session6
When the xfrm device is set to the qdisc of the sfb type, the cb field
of the sent skb may be modified during enqueuing. Then,
slab-use-after-free may occur when the xfrm device sends IPv6 packets.
The stack information is as follows:
BUG: KASAN: slab-use-after-free in decode_session6+0x103f/0x1890
Read of size 1 at addr ffff8881111458ef by task swapper/3/0
CPU: 3 PID: 0 Comm: swapper/3 Not tainted 6.4.0-next-20230707 #409
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014
Call Trace:
<IRQ>
dump_stack_lvl+0xd9/0x150
print_address_description.constprop.0+0x2c/0x3c0
kasan_report+0x11d/0x130
decode_session6+0x103f/0x1890
__xfrm_decode_session+0x54/0xb0
xfrmi_xmit+0x173/0x1ca0
dev_hard_start_xmit+0x187/0x700
sch_direct_xmit+0x1a3/0xc30
__qdisc_run+0x510/0x17a0
__dev_queue_xmit+0x2215/0x3b10
neigh_connected_output+0x3c2/0x550
ip6_finish_output2+0x55a/0x1550
ip6_finish_output+0x6b9/0x1270
ip6_output+0x1f1/0x540
ndisc_send_skb+0xa63/0x1890
ndisc_send_rs+0x132/0x6f0
addrconf_rs_timer+0x3f1/0x870
call_timer_fn+0x1a0/0x580
expire_timers+0x29b/0x4b0
run_timer_softirq+0x326/0x910
__do_softirq+0x1d4/0x905
irq_exit_rcu+0xb7/0x120
sysvec_apic_timer_interrupt+0x97/0xc0
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:intel_idle_hlt+0x23/0x30
Code: 1f 84 00 00 00 00 00 f3 0f 1e fa 41 54 41 89 d4 0f 1f 44 00 00 66 90 0f 1f 44 00 00 0f 00 2d c4 9f ab 00 0f 1f 44 00 00 fb f4 <fa> 44 89 e0 41 5c c3 66 0f 1f 44 00 00 f3 0f 1e fa 41 54 41 89 d4
RSP: 0018:ffffc90000197d78 EFLAGS: 00000246
RAX: 00000000000a83c3 RBX: ffffe8ffffd09c50 RCX: ffffffff8a22d8e5
RDX: 0000000000000001 RSI: ffffffff8d3f8080 RDI: ffffe8ffffd09c50
RBP: ffffffff8d3f8080 R08: 0000000000000001 R09: ffffed1026ba6d9d
R10: ffff888135d36ceb R11: 0000000000000001 R12: 0000000000000001
R13: ffffffff8d3f8100 R14: 0000000000000001 R15: 0000000000000000
cpuidle_enter_state+0xd3/0x6f0
cpuidle_enter+0x4e/0xa0
do_idle+0x2fe/0x3c0
cpu_startup_entry+0x18/0x20
start_secondary+0x200/0x290
secondary_startup_64_no_verify+0x167/0x16b
</TASK>
Allocated by task 939:
kasan_save_stack+0x22/0x40
kasan_set_track+0x25/0x30
__kasan_slab_alloc+0x7f/0x90
kmem_cache_alloc_node+0x1cd/0x410
kmalloc_reserve+0x165/0x270
__alloc_skb+0x129/0x330
inet6_ifa_notify+0x118/0x230
__ipv6_ifa_notify+0x177/0xbe0
addrconf_dad_completed+0x133/0xe00
addrconf_dad_work+0x764/0x1390
process_one_work+0xa32/0x16f0
worker_thread+0x67d/0x10c0
kthread+0x344/0x440
ret_from_fork+0x1f/0x30
The buggy address belongs to the object at ffff888111145800
which belongs to the cache skbuff_small_head of size 640
The buggy address is located 239 bytes inside of
freed 640-byte region [ffff888111145800, ffff888111145a80)
As commit f855691975bb ("xfrm6: Fix the nexthdr offset in
_decode_session6.") showed, xfrm_decode_session was originally intended
only for the receive path. IP6CB(skb)->nhoff is not set during
transmission. Therefore, set the cb field in the skb to 0 before
sending packets.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
ext4: allow ext4_get_group_info() to fail
Previously, ext4_get_group_info() would treat an invalid group number
as BUG(), since in theory it should never happen. However, if a
malicious attaker (or fuzzer) modifies the superblock via the block
device while it is the file system is mounted, it is possible for
s_first_data_block to get set to a very large number. In that case,
when calculating the block group of some block number (such as the
starting block of a preallocation region), could result in an
underflow and very large block group number. Then the BUG_ON check in
ext4_get_group_info() would fire, resutling in a denial of service
attack that can be triggered by root or someone with write access to
the block device.
For a quality of implementation perspective, it's best that even if
the system administrator does something that they shouldn't, that it
will not trigger a BUG. So instead of BUG'ing, ext4_get_group_info()
will call ext4_error and return NULL. We also add fallback code in
all of the callers of ext4_get_group_info() that it might NULL.
Also, since ext4_get_group_info() was already borderline to be an
inline function, un-inline it. The results in a next reduction of the
compiled text size of ext4 by roughly 2k.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
start_kernel: Add __no_stack_protector function attribute
Back during the discussion of
commit a9a3ed1eff36 ("x86: Fix early boot crash on gcc-10, third try")
we discussed the need for a function attribute to control the omission
of stack protectors on a per-function basis; at the time Clang had
support for no_stack_protector but GCC did not. This was fixed in
gcc-11. Now that the function attribute is available, let's start using
it.
Callers of boot_init_stack_canary need to use this function attribute
unless they're compiled with -fno-stack-protector, otherwise the canary
stored in the stack slot of the caller will differ upon the call to
boot_init_stack_canary. This will lead to a call to __stack_chk_fail()
then panic.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
lib: cpu_rmap: Avoid use after free on rmap->obj array entries
When calling irq_set_affinity_notifier() with NULL at the notify
argument, it will cause freeing of the glue pointer in the
corresponding array entry but will leave the pointer in the array. A
subsequent call to free_irq_cpu_rmap() will try to free this entry again
leading to possible use after free.
Fix that by setting NULL to the array entry and checking that we have
non-zero at the array entry when iterating over the array in
free_irq_cpu_rmap().
The current code does not suffer from this since there are no cases
where irq_set_affinity_notifier(irq, NULL) (note the NULL passed for the
notify arg) is called, followed by a call to free_irq_cpu_rmap() so we
don't hit and issue. Subsequent patches in this series excersize this
flow, hence the required fix.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
fs: jfs: Fix UBSAN: array-index-out-of-bounds in dbAllocDmapLev
Syzkaller reported the following issue:
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:1965:6
index -84 is out of range for type 's8[341]' (aka 'signed char[341]')
CPU: 1 PID: 4995 Comm: syz-executor146 Not tainted 6.4.0-rc6-syzkaller-00037-gb6dad5178cea #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:217 [inline]
__ubsan_handle_out_of_bounds+0x11c/0x150 lib/ubsan.c:348
dbAllocDmapLev+0x3e5/0x430 fs/jfs/jfs_dmap.c:1965
dbAllocCtl+0x113/0x920 fs/jfs/jfs_dmap.c:1809
dbAllocAG+0x28f/0x10b0 fs/jfs/jfs_dmap.c:1350
dbAlloc+0x658/0xca0 fs/jfs/jfs_dmap.c:874
dtSplitUp fs/jfs/jfs_dtree.c:974 [inline]
dtInsert+0xda7/0x6b00 fs/jfs/jfs_dtree.c:863
jfs_create+0x7b6/0xbb0 fs/jfs/namei.c:137
lookup_open fs/namei.c:3492 [inline]
open_last_lookups fs/namei.c:3560 [inline]
path_openat+0x13df/0x3170 fs/namei.c:3788
do_filp_open+0x234/0x490 fs/namei.c:3818
do_sys_openat2+0x13f/0x500 fs/open.c:1356
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x247/0x290 fs/open.c:1383
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f1f4e33f7e9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc21129578 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1f4e33f7e9
RDX: 000000000000275a RSI: 0000000020000040 RDI: 00000000ffffff9c
RBP: 00007f1f4e2ff080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1f4e2ff110
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
The bug occurs when the dbAllocDmapLev()function attempts to access
dp->tree.stree[leafidx + LEAFIND] while the leafidx value is negative.
To rectify this, the patch introduces a safeguard within the
dbAllocDmapLev() function. A check has been added to verify if leafidx is
negative. If it is, the function immediately returns an I/O error, preventing
any further execution that could potentially cause harm.
Tested via syzbot.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
ubi: ubi_wl_put_peb: Fix infinite loop when wear-leveling work failed
Following process will trigger an infinite loop in ubi_wl_put_peb():
ubifs_bgt ubi_bgt
ubifs_leb_unmap
ubi_leb_unmap
ubi_eba_unmap_leb
ubi_wl_put_peb wear_leveling_worker
e1 = rb_entry(rb_first(&ubi->used)
e2 = get_peb_for_wl(ubi)
ubi_io_read_vid_hdr // return err (flash fault)
out_error:
ubi->move_from = ubi->move_to = NULL
wl_entry_destroy(ubi, e1)
ubi->lookuptbl[e->pnum] = NULL
retry:
e = ubi->lookuptbl[pnum]; // return NULL
if (e == ubi->move_from) { // NULL == NULL gets true
goto retry; // infinite loop !!!
$ top
PID USER PR NI VIRT RES SHR S %CPU %MEM COMMAND
7676 root 20 0 0 0 0 R 100.0 0.0 ubifs_bgt0_0
Fix it by:
1) Letting ubi_wl_put_peb() returns directly if wearl leveling entry has
been removed from 'ubi->lookuptbl'.
2) Using 'ubi->wl_lock' protecting wl entry deletion to preventing an
use-after-free problem for wl entry in ubi_wl_put_peb().
Fetch a reproducer in [Link].
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu/gfx: disable gfx9 cp_ecc_error_irq only when enabling legacy gfx ras
gfx9 cp_ecc_error_irq is only enabled when legacy gfx ras is assert.
So in gfx_v9_0_hw_fini, interrupt disablement for cp_ecc_error_irq
should be executed under such condition, otherwise, an amdgpu_irq_put
calltrace will occur.
[ 7283.170322] RIP: 0010:amdgpu_irq_put+0x45/0x70 [amdgpu]
[ 7283.170964] RSP: 0018:ffff9a5fc3967d00 EFLAGS: 00010246
[ 7283.170967] RAX: ffff98d88afd3040 RBX: ffff98d89da20000 RCX: 0000000000000000
[ 7283.170969] RDX: 0000000000000000 RSI: ffff98d89da2bef8 RDI: ffff98d89da20000
[ 7283.170971] RBP: ffff98d89da20000 R08: ffff98d89da2ca18 R09: 0000000000000006
[ 7283.170973] R10: ffffd5764243c008 R11: 0000000000000000 R12: 0000000000001050
[ 7283.170975] R13: ffff98d89da38978 R14: ffffffff999ae15a R15: ffff98d880130105
[ 7283.170978] FS: 0000000000000000(0000) GS:ffff98d996f00000(0000) knlGS:0000000000000000
[ 7283.170981] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7283.170983] CR2: 00000000f7a9d178 CR3: 00000001c42ea000 CR4: 00000000003506e0
[ 7283.170986] Call Trace:
[ 7283.170988] <TASK>
[ 7283.170989] gfx_v9_0_hw_fini+0x1c/0x6d0 [amdgpu]
[ 7283.171655] amdgpu_device_ip_suspend_phase2+0x101/0x1a0 [amdgpu]
[ 7283.172245] amdgpu_device_suspend+0x103/0x180 [amdgpu]
[ 7283.172823] amdgpu_pmops_freeze+0x21/0x60 [amdgpu]
[ 7283.173412] pci_pm_freeze+0x54/0xc0
[ 7283.173419] ? __pfx_pci_pm_freeze+0x10/0x10
[ 7283.173425] dpm_run_callback+0x98/0x200
[ 7283.173430] __device_suspend+0x164/0x5f0
v2: drop gfx11 as it's fixed in a different solution by retiring cp_ecc_irq funcs(Hawking)
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
ubifs: Fix memory leak in alloc_wbufs()
kmemleak reported a sequence of memory leaks, and show them as following:
unreferenced object 0xffff8881575f8400 (size 1024):
comm "mount", pid 19625, jiffies 4297119604 (age 20.383s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff8176cecd>] __kmalloc+0x4d/0x150
[<ffffffffa0406b2b>] ubifs_mount+0x307b/0x7170 [ubifs]
[<ffffffff819fa8fd>] legacy_get_tree+0xed/0x1d0
[<ffffffff81936f2d>] vfs_get_tree+0x7d/0x230
[<ffffffff819b2bd4>] path_mount+0xdd4/0x17b0
[<ffffffff819b37aa>] __x64_sys_mount+0x1fa/0x270
[<ffffffff83c14295>] do_syscall_64+0x35/0x80
[<ffffffff83e0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
unreferenced object 0xffff8881798a6e00 (size 512):
comm "mount", pid 19677, jiffies 4297121912 (age 37.816s)
hex dump (first 32 bytes):
6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
backtrace:
[<ffffffff8176cecd>] __kmalloc+0x4d/0x150
[<ffffffffa0418342>] ubifs_wbuf_init+0x52/0x480 [ubifs]
[<ffffffffa0406ca5>] ubifs_mount+0x31f5/0x7170 [ubifs]
[<ffffffff819fa8fd>] legacy_get_tree+0xed/0x1d0
[<ffffffff81936f2d>] vfs_get_tree+0x7d/0x230
[<ffffffff819b2bd4>] path_mount+0xdd4/0x17b0
[<ffffffff819b37aa>] __x64_sys_mount+0x1fa/0x270
[<ffffffff83c14295>] do_syscall_64+0x35/0x80
[<ffffffff83e0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
The problem is that the ubifs_wbuf_init() returns an error in the
loop which in the alloc_wbufs(), then the wbuf->buf and wbuf->inodes
that were successfully alloced before are not freed.
Fix it by adding error hanging path in alloc_wbufs() which frees
the memory alloced before when ubifs_wbuf_init() returns an error.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-01