In the Linux kernel, the following vulnerability has been resolved:
ext2/dax: Fix ext2_setsize when len is page aligned
PAGE_ALIGN(x) macro gives the next highest value which is multiple of
pagesize. But if x is already page aligned then it simply returns x.
So, if x passed is 0 in dax_zero_range() function, that means the
length gets passed as 0 to ->iomap_begin().
In ext2 it then calls ext2_get_blocks -> max_blocks as 0 and hits bug_on
here in ext2_get_blocks().
BUG_ON(maxblocks == 0);
Instead we should be calling dax_truncate_page() here which takes
care of it. i.e. it only calls dax_zero_range if the offset is not
page/block aligned.
This can be easily triggered with following on fsdax mounted pmem
device.
dd if=/dev/zero of=file count=1 bs=512
truncate -s 0 file
[79.525838] EXT2-fs (pmem0): DAX enabled. Warning: EXPERIMENTAL, use at your own risk
[79.529376] ext2 filesystem being mounted at /mnt1/test supports timestamps until 2038 (0x7fffffff)
[93.793207] ------------[ cut here ]------------
[93.795102] kernel BUG at fs/ext2/inode.c:637!
[93.796904] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[93.798659] CPU: 0 PID: 1192 Comm: truncate Not tainted 6.3.0-rc2-xfstests-00056-g131086faa369 #139
[93.806459] RIP: 0010:ext2_get_blocks.constprop.0+0x524/0x610
<...>
[93.835298] Call Trace:
[93.836253] <TASK>
[93.837103] ? lock_acquire+0xf8/0x110
[93.838479] ? d_lookup+0x69/0xd0
[93.839779] ext2_iomap_begin+0xa7/0x1c0
[93.841154] iomap_iter+0xc7/0x150
[93.842425] dax_zero_range+0x6e/0xa0
[93.843813] ext2_setsize+0x176/0x1b0
[93.845164] ext2_setattr+0x151/0x200
[93.846467] notify_change+0x341/0x4e0
[93.847805] ? lock_acquire+0xf8/0x110
[93.849143] ? do_truncate+0x74/0xe0
[93.850452] ? do_truncate+0x84/0xe0
[93.851739] do_truncate+0x84/0xe0
[93.852974] do_sys_ftruncate+0x2b4/0x2f0
[93.854404] do_syscall_64+0x3f/0x90
[93.855789] entry_SYSCALL_64_after_hwframe+0x72/0xdc
References
Configurations
Configuration 1 (hide)
|
History
10 Dec 2025, 18:41
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| References | () https://git.kernel.org/stable/c/5cee8bfb8cbd99c97aff85d2bf066b6a496e13ab - Patch | |
| References | () https://git.kernel.org/stable/c/9e54fd14bd143c261e52fde74355e85e9526c58c - Patch | |
| References | () https://git.kernel.org/stable/c/fcced95b6ba2a507a83b8b3e0358a8ac16b13e35 - Patch | |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| First Time |
Linux
Linux linux Kernel |
|
| CWE | CWE-617 |
16 Sep 2025, 17:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2025-09-16 17:15
Updated : 2025-12-10 18:41
NVD link : CVE-2023-53323
Mitre link : CVE-2023-53323
CVE.ORG link : CVE-2023-53323
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-617
Reachable Assertion