Linux: >> Linux Kernel >> 2.6.15.3 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
jfs: validate AG parameters in dbMount() to prevent crashes
Validate db_agheight, db_agwidth, and db_agstart in dbMount to catch
corrupted metadata early and avoid undefined behavior in dbAllocAG.
Limits are derived from L2LPERCTL, LPERCTL/MAXAG, and CTLTREESIZE:
- agheight: 0 to L2LPERCTL/2 (0 to 5) ensures shift
(L2LPERCTL - 2*agheight) >= 0.
- agwidth: 1 to min(LPERCTL/MAXAG, 2^(L2LPERCTL - 2*agheight))
ensures agperlev >= 1.
- Ranges: 1-8 (agheight 0-3), 1-4 (agheight 4), 1 (agheight 5).
- LPERCTL/MAXAG = 1024/128 = 8 limits leaves per AG;
2^(10 - 2*agheight) prevents division to 0.
- agstart: 0 to CTLTREESIZE-1 - agwidth*(MAXAG-1) keeps ti within
stree (size 1365).
- Ranges: 0-1237 (agwidth 1), 0-348 (agwidth 8).
UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:1400:9
shift exponent -335544310 is negative
CPU: 0 UID: 0 PID: 5822 Comm: syz-executor130 Not tainted 6.14.0-rc5-syzkaller #0
Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
ubsan_epilogue lib/ubsan.c:231 [inline]
__ubsan_handle_shift_out_of_bounds+0x3c8/0x420 lib/ubsan.c:468
dbAllocAG+0x1087/0x10b0 fs/jfs/jfs_dmap.c:1400
dbDiscardAG+0x352/0xa20 fs/jfs/jfs_dmap.c:1613
jfs_ioc_trim+0x45a/0x6b0 fs/jfs/jfs_discard.c:105
jfs_ioctl+0x2cd/0x3e0 fs/jfs/ioctl.c:131
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-07-04
In the Linux kernel, the following vulnerability has been resolved:
NFSD: fix race between nfsd registration and exports_proc
As of now nfsd calls create_proc_exports_entry() at start of init_nfsd
and cleanup by remove_proc_entry() at last of exit_nfsd.
Which causes kernel OOPs if there is race between below 2 operations:
(i) exportfs -r
(ii) mount -t nfsd none /proc/fs/nfsd
for 5.4 kernel ARM64:
CPU 1:
el1_irq+0xbc/0x180
arch_counter_get_cntvct+0x14/0x18
running_clock+0xc/0x18
preempt_count_add+0x88/0x110
prep_new_page+0xb0/0x220
get_page_from_freelist+0x2d8/0x1778
__alloc_pages_nodemask+0x15c/0xef0
__vmalloc_node_range+0x28c/0x478
__vmalloc_node_flags_caller+0x8c/0xb0
kvmalloc_node+0x88/0xe0
nfsd_init_net+0x6c/0x108 [nfsd]
ops_init+0x44/0x170
register_pernet_operations+0x114/0x270
register_pernet_subsys+0x34/0x50
init_nfsd+0xa8/0x718 [nfsd]
do_one_initcall+0x54/0x2e0
CPU 2 :
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
PC is at : exports_net_open+0x50/0x68 [nfsd]
Call trace:
exports_net_open+0x50/0x68 [nfsd]
exports_proc_open+0x2c/0x38 [nfsd]
proc_reg_open+0xb8/0x198
do_dentry_open+0x1c4/0x418
vfs_open+0x38/0x48
path_openat+0x28c/0xf18
do_filp_open+0x70/0xe8
do_sys_open+0x154/0x248
Sometimes it crashes at exports_net_open() and sometimes cache_seq_next_rcu().
and same is happening on latest 6.14 kernel as well:
[ 0.000000] Linux version 6.14.0-rc5-next-20250304-dirty
...
[ 285.455918] Unable to handle kernel paging request at virtual address 00001f4800001f48
...
[ 285.464902] pc : cache_seq_next_rcu+0x78/0xa4
...
[ 285.469695] Call trace:
[ 285.470083] cache_seq_next_rcu+0x78/0xa4 (P)
[ 285.470488] seq_read+0xe0/0x11c
[ 285.470675] proc_reg_read+0x9c/0xf0
[ 285.470874] vfs_read+0xc4/0x2fc
[ 285.471057] ksys_read+0x6c/0xf4
[ 285.471231] __arm64_sys_read+0x1c/0x28
[ 285.471428] invoke_syscall+0x44/0x100
[ 285.471633] el0_svc_common.constprop.0+0x40/0xe0
[ 285.471870] do_el0_svc_compat+0x1c/0x34
[ 285.472073] el0_svc_compat+0x2c/0x80
[ 285.472265] el0t_32_sync_handler+0x90/0x140
[ 285.472473] el0t_32_sync+0x19c/0x1a0
[ 285.472887] Code: f9400885 93407c23 937d7c27 11000421 (f86378a3)
[ 285.473422] ---[ end trace 0000000000000000 ]---
It reproduced simply with below script:
while [ 1 ]
do
/exportfs -r
done &
while [ 1 ]
do
insmod /nfsd.ko
mount -t nfsd none /proc/fs/nfsd
umount /proc/fs/nfsd
rmmod nfsd
done &
So exporting interfaces to user space shall be done at last and
cleanup at first place.
With change there is no Kernel OOPs.
CVSS Score
4.7
EPSS Score
0.0
Published
2025-07-04
In the Linux kernel, the following vulnerability has been resolved:
fbdev: Fix fb_set_var to prevent null-ptr-deref in fb_videomode_to_var
If fb_add_videomode() in fb_set_var() fails to allocate memory for
fb_videomode, later it may lead to a null-ptr dereference in
fb_videomode_to_var(), as the fb_info is registered while not having the
mode in modelist that is expected to be there, i.e. the one that is
described in fb_info->var.
================================================================
general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 30371 Comm: syz-executor.1 Not tainted 5.10.226-syzkaller #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:fb_videomode_to_var+0x24/0x610 drivers/video/fbdev/core/modedb.c:901
Call Trace:
display_to_var+0x3a/0x7c0 drivers/video/fbdev/core/fbcon.c:929
fbcon_resize+0x3e2/0x8f0 drivers/video/fbdev/core/fbcon.c:2071
resize_screen drivers/tty/vt/vt.c:1176 [inline]
vc_do_resize+0x53a/0x1170 drivers/tty/vt/vt.c:1263
fbcon_modechanged+0x3ac/0x6e0 drivers/video/fbdev/core/fbcon.c:2720
fbcon_update_vcs+0x43/0x60 drivers/video/fbdev/core/fbcon.c:2776
do_fb_ioctl+0x6d2/0x740 drivers/video/fbdev/core/fbmem.c:1128
fb_ioctl+0xe7/0x150 drivers/video/fbdev/core/fbmem.c:1203
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739
do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x67/0xd1
================================================================
The reason is that fb_info->var is being modified in fb_set_var(), and
then fb_videomode_to_var() is called. If it fails to add the mode to
fb_info->modelist, fb_set_var() returns error, but does not restore the
old value of fb_info->var. Restore fb_info->var on failure the same way
it is done earlier in the function.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-04
In the Linux kernel, the following vulnerability has been resolved:
fbdev: Fix do_register_framebuffer to prevent null-ptr-deref in fb_videomode_to_var
If fb_add_videomode() in do_register_framebuffer() fails to allocate
memory for fb_videomode, it will later lead to a null-ptr dereference in
fb_videomode_to_var(), as the fb_info is registered while not having the
mode in modelist that is expected to be there, i.e. the one that is
described in fb_info->var.
================================================================
general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 30371 Comm: syz-executor.1 Not tainted 5.10.226-syzkaller #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:fb_videomode_to_var+0x24/0x610 drivers/video/fbdev/core/modedb.c:901
Call Trace:
display_to_var+0x3a/0x7c0 drivers/video/fbdev/core/fbcon.c:929
fbcon_resize+0x3e2/0x8f0 drivers/video/fbdev/core/fbcon.c:2071
resize_screen drivers/tty/vt/vt.c:1176 [inline]
vc_do_resize+0x53a/0x1170 drivers/tty/vt/vt.c:1263
fbcon_modechanged+0x3ac/0x6e0 drivers/video/fbdev/core/fbcon.c:2720
fbcon_update_vcs+0x43/0x60 drivers/video/fbdev/core/fbcon.c:2776
do_fb_ioctl+0x6d2/0x740 drivers/video/fbdev/core/fbmem.c:1128
fb_ioctl+0xe7/0x150 drivers/video/fbdev/core/fbmem.c:1203
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739
do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x67/0xd1
================================================================
Even though fbcon_init() checks beforehand if fb_match_mode() in
var_to_display() fails, it can not prevent the panic because fbcon_init()
does not return error code. Considering this and the comment in the code
about fb_match_mode() returning NULL - "This should not happen" - it is
better to prevent registering the fb_info if its mode was not set
successfully. Also move fb_add_videomode() closer to the beginning of
do_register_framebuffer() to avoid having to do the cleanup on fail.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-04
In the Linux kernel, the following vulnerability has been resolved:
jfs: fix array-index-out-of-bounds read in add_missing_indices
stbl is s8 but it must contain offsets into slot which can go from 0 to
127.
Added a bound check for that error and return -EIO if the check fails.
Also make jfs_readdir return with error if add_missing_indices returns
with an error.
CVSS Score
7.1
EPSS Score
0.0
Published
2025-07-04
In the Linux kernel, the following vulnerability has been resolved:
smb: client: add NULL check in automount_fullpath
page is checked for null in __build_path_from_dentry_optional_prefix
when tcon->origin_fullpath is not set. However, the check is missing when
it is set.
Add a check to prevent a potential NULL pointer dereference.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-04
In the Linux kernel, the following vulnerability has been resolved:
fbcon: Make sure modelist not set on unregistered console
It looks like attempting to write to the "store_modes" sysfs node will
run afoul of unregistered consoles:
UBSAN: array-index-out-of-bounds in drivers/video/fbdev/core/fbcon.c:122:28
index -1 is out of range for type 'fb_info *[32]'
...
fbcon_info_from_console+0x192/0x1a0 drivers/video/fbdev/core/fbcon.c:122
fbcon_new_modelist+0xbf/0x2d0 drivers/video/fbdev/core/fbcon.c:3048
fb_new_modelist+0x328/0x440 drivers/video/fbdev/core/fbmem.c:673
store_modes+0x1c9/0x3e0 drivers/video/fbdev/core/fbsysfs.c:113
dev_attr_store+0x55/0x80 drivers/base/core.c:2439
static struct fb_info *fbcon_registered_fb[FB_MAX];
...
static signed char con2fb_map[MAX_NR_CONSOLES];
...
static struct fb_info *fbcon_info_from_console(int console)
...
return fbcon_registered_fb[con2fb_map[console]];
If con2fb_map contains a -1 things go wrong here. Instead, return NULL,
as callers of fbcon_info_from_console() are trying to compare against
existing "info" pointers, so error handling should kick in correctly.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-07-04
In the Linux kernel, the following vulnerability has been resolved:
atm: Revert atm_account_tx() if copy_from_iter_full() fails.
In vcc_sendmsg(), we account skb->truesize to sk->sk_wmem_alloc by
atm_account_tx().
It is expected to be reverted by atm_pop_raw() later called by
vcc->dev->ops->send(vcc, skb).
However, vcc_sendmsg() misses the same revert when copy_from_iter_full()
fails, and then we will leak a socket.
Let's factorise the revert part as atm_return_tx() and call it in
the failure path.
Note that the corresponding sk_wmem_alloc operation can be found in
alloc_tx() as of the blamed commit.
$ git blame -L:alloc_tx net/atm/common.c c55fa3cccbc2c~
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-04
In the Linux kernel, the following vulnerability has been resolved:
net_sched: sch_sfq: reject invalid perturb period
Gerrard Tai reported that SFQ perturb_period has no range check yet,
and this can be used to trigger a race condition fixed in a separate patch.
We want to make sure ctl->perturb_period * HZ will not overflow
and is positive.
tc qd add dev lo root sfq perturb -10 # negative value : error
Error: sch_sfq: invalid perturb period.
tc qd add dev lo root sfq perturb 1000000000 # too big : error
Error: sch_sfq: invalid perturb period.
tc qd add dev lo root sfq perturb 2000000 # acceptable value
tc -s -d qd sh dev lo
qdisc sfq 8005: root refcnt 2 limit 127p quantum 64Kb depth 127 flows 128 divisor 1024 perturb 2000000sec
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-04
In the Linux kernel, the following vulnerability has been resolved:
atm: atmtcp: Free invalid length skb in atmtcp_c_send().
syzbot reported the splat below. [0]
vcc_sendmsg() copies data passed from userspace to skb and passes
it to vcc->dev->ops->send().
atmtcp_c_send() accesses skb->data as struct atmtcp_hdr after
checking if skb->len is 0, but it's not enough.
Also, when skb->len == 0, skb and sk (vcc) were leaked because
dev_kfree_skb() is not called and sk_wmem_alloc adjustment is missing
to revert atm_account_tx() in vcc_sendmsg(), which is expected
to be done in atm_pop_raw().
Let's properly free skb with an invalid length in atmtcp_c_send().
[0]:
BUG: KMSAN: uninit-value in atmtcp_c_send+0x255/0xed0 drivers/atm/atmtcp.c:294
atmtcp_c_send+0x255/0xed0 drivers/atm/atmtcp.c:294
vcc_sendmsg+0xd7c/0xff0 net/atm/common.c:644
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x330/0x3d0 net/socket.c:727
____sys_sendmsg+0x7e0/0xd80 net/socket.c:2566
___sys_sendmsg+0x271/0x3b0 net/socket.c:2620
__sys_sendmsg net/socket.c:2652 [inline]
__do_sys_sendmsg net/socket.c:2657 [inline]
__se_sys_sendmsg net/socket.c:2655 [inline]
__x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2655
x64_sys_call+0x32fb/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:47
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Uninit was created at:
slab_post_alloc_hook mm/slub.c:4154 [inline]
slab_alloc_node mm/slub.c:4197 [inline]
kmem_cache_alloc_node_noprof+0x818/0xf00 mm/slub.c:4249
kmalloc_reserve+0x13c/0x4b0 net/core/skbuff.c:579
__alloc_skb+0x347/0x7d0 net/core/skbuff.c:670
alloc_skb include/linux/skbuff.h:1336 [inline]
vcc_sendmsg+0xb40/0xff0 net/atm/common.c:628
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x330/0x3d0 net/socket.c:727
____sys_sendmsg+0x7e0/0xd80 net/socket.c:2566
___sys_sendmsg+0x271/0x3b0 net/socket.c:2620
__sys_sendmsg net/socket.c:2652 [inline]
__do_sys_sendmsg net/socket.c:2657 [inline]
__se_sys_sendmsg net/socket.c:2655 [inline]
__x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2655
x64_sys_call+0x32fb/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:47
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
CPU: 1 UID: 0 PID: 5798 Comm: syz-executor192 Not tainted 6.16.0-rc1-syzkaller-00010-g2c4a1f3fe03e #0 PREEMPT(undef)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-04