Описание
In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix OOBs when building SMB2_IOCTL request
When using encryption, either enforced by the server or when using
'seal' mount option, the client will squash all compound request buffers
down for encryption into a single iov in smb2_set_next_command().
SMB2_ioctl_init() allocates a small buffer (448 bytes) to hold the
SMB2_IOCTL request in the first iov, and if the user passes an input
buffer that is greater than 328 bytes, smb2_set_next_command() will
end up writing off the end of @rqst->iov[0].iov_base as shown below:
mount.cifs //srv/share /mnt -o ...,seal
ln -s $(perl -e "print('a')for 1..1024") /mnt/link
BUG: KASAN: slab-out-of-bounds in
smb2_set_next_command.cold+0x1d6/0x24c [cifs]
Write of size 4116 at addr ffff8881148fcab8 by task ln/859
CPU: 1 UID: 0 PID: 859 Comm: ln Not tainted 6.12.0-rc3 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
1.16.3-2.fc40 04/01/2014
Call Trace:
dump_stack_lvl+0x5d/0x80
? smb2_set_next_command.cold+0x1d6/0x24c [cifs]
print_report+0x156/0x4d9
? smb2_set_next_command.cold+0x1d6/0x24c [cifs]
? __virt_addr_valid+0x145/0x310
? __phys_addr+0x46/0x90
? smb2_set_next_command.cold+0x1d6/0x24c [cifs]
kasan_report+0xda/0x110
? smb2_set_next_command.cold+0x1d6/0x24c [cifs]
kasan_check_range+0x10f/0x1f0
__asan_memcpy+0x3c/0x60
smb2_set_next_command.cold+0x1d6/0x24c [cifs]
smb2_compound_op+0x238c/0x3840 [cifs]
? kasan_save_track+0x14/0x30
? kasan_save_free_info+0x3b/0x70
? vfs_symlink+0x1a1/0x2c0
? do_symlinkat+0x108/0x1c0
? __pfx_smb2_compound_op+0x10/0x10 [cifs]
? kmem_cache_free+0x118/0x3e0
? cifs_get_writable_path+0xeb/0x1a0 [cifs]
smb2_get_reparse_inode+0x423/0x540 [cifs]
? __pfx_smb2_get_reparse_inode+0x10/0x10 [cifs]
? rcu_is_watching+0x20/0x50
? __kmalloc_noprof+0x37c/0x480
? smb2_create_reparse_symlink+0x257/0x490 [cifs]
? smb2_create_reparse_symlink+0x38f/0x490 [cifs]
smb2_create_reparse_symlink+0x38f/0x490 [cifs]
? __pfx_smb2_create_reparse_symlink+0x10/0x10 [cifs]
? find_held_lock+0x8a/0xa0
? hlock_class+0x32/0xb0
? __build_path_from_dentry_optional_prefix+0x19d/0x2e0 [cifs]
cifs_symlink+0x24f/0x960 [cifs]
? __pfx_make_vfsuid+0x10/0x10
? __pfx_cifs_symlink+0x10/0x10 [cifs]
? make_vfsgid+0x6b/0xc0
? generic_permission+0x96/0x2d0
vfs_symlink+0x1a1/0x2c0
do_symlinkat+0x108/0x1c0
? __pfx_do_symlinkat+0x10/0x10
? strncpy_from_user+0xaa/0x160
__x64_sys_symlinkat+0xb9/0xf0
do_syscall_64+0xbb/0x1d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f08d75c13bb
A flaw was found in the cifs module in the Linux kernel. When building SMB2_IOCTL requests using encryption, either enforced by the server or using the 'seal' mount option, an out-of-bounds write can be triggered when the user passes an input buffer greater than 328 bytes, resulting in memory corruption and a kernel crash.
Отчет
To exploit this flaw, an attacker needs local access to the system and SMB encryption must be enabled, limiting the impact of this issue. For these reasons, this flaw has been rated with a moderate severity. The cifs module in the Linux kernel as shipped in Red Hat Enterprise Linux 8 is not affected by this vulnerability because the vulnerable code was introduced in a newer version of the Linux kernel.
Меры по смягчению последствий
Consider temporarily disabling SMB encryption and monitor the system for unusual behavior, such as crashes, as it may indicate exploitation attempts.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Out of support scope | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Will not fix | ||
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2025:6966 | 13.05.2025 |
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2025:6966 | 13.05.2025 |
Показывать по
Дополнительная информация
Статус:
EPSS
7.8 High
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix OOBs when building SMB2_IOCTL request When using encryption, either enforced by the server or when using 'seal' mount option, the client will squash all compound request buffers down for encryption into a single iov in smb2_set_next_command(). SMB2_ioctl_init() allocates a small buffer (448 bytes) to hold the SMB2_IOCTL request in the first iov, and if the user passes an input buffer that is greater than 328 bytes, smb2_set_next_command() will end up writing off the end of @rqst->iov[0].iov_base as shown below: mount.cifs //srv/share /mnt -o ...,seal ln -s $(perl -e "print('a')for 1..1024") /mnt/link BUG: KASAN: slab-out-of-bounds in smb2_set_next_command.cold+0x1d6/0x24c [cifs] Write of size 4116 at addr ffff8881148fcab8 by task ln/859 CPU: 1 UID: 0 PID: 859 Comm: ln Not tainted 6.12.0-rc3 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 Call Trace: <TASK> ...
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix OOBs when building SMB2_IOCTL request When using encryption, either enforced by the server or when using 'seal' mount option, the client will squash all compound request buffers down for encryption into a single iov in smb2_set_next_command(). SMB2_ioctl_init() allocates a small buffer (448 bytes) to hold the SMB2_IOCTL request in the first iov, and if the user passes an input buffer that is greater than 328 bytes, smb2_set_next_command() will end up writing off the end of @rqst->iov[0].iov_base as shown below: mount.cifs //srv/share /mnt -o ...,seal ln -s $(perl -e "print('a')for 1..1024") /mnt/link BUG: KASAN: slab-out-of-bounds in smb2_set_next_command.cold+0x1d6/0x24c [cifs] Write of size 4116 at addr ffff8881148fcab8 by task ln/859 CPU: 1 UID: 0 PID: 859 Comm: ln Not tainted 6.12.0-rc3 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 Call
In the Linux kernel, the following vulnerability has been resolved: s ...
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix OOBs when building SMB2_IOCTL request When using encryption, either enforced by the server or when using 'seal' mount option, the client will squash all compound request buffers down for encryption into a single iov in smb2_set_next_command(). SMB2_ioctl_init() allocates a small buffer (448 bytes) to hold the SMB2_IOCTL request in the first iov, and if the user passes an input buffer that is greater than 328 bytes, smb2_set_next_command() will end up writing off the end of @rqst->iov[0].iov_base as shown below: mount.cifs //srv/share /mnt -o ...,seal ln -s $(perl -e "print('a')for 1..1024") /mnt/link BUG: KASAN: slab-out-of-bounds in smb2_set_next_command.cold+0x1d6/0x24c [cifs] Write of size 4116 at addr ffff8881148fcab8 by task ln/859 CPU: 1 UID: 0 PID: 859 Comm: ln Not tainted 6.12.0-rc3 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 C...
EPSS
7.8 High
CVSS3