CVE-2025-38415
published 2025-07-25CVE-2025-38415: In the Linux kernel, the following vulnerability has been resolved: Squashfs: check return result of sb_min_blocksize Syzkaller reports an "UBSAN…
high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
In the Linux kernel, the following vulnerability has been resolved:
Squashfs: check return result of sb_min_blocksize
Syzkaller reports an "UBSAN: shift-out-of-bounds in squashfs_bio_read" bug.
Syzkaller forks multiple processes which after mounting the Squashfs
filesystem, issues an ioctl("/dev/loop0", LOOP_SET_BLOCK_SIZE, 0x8000).
Now if this ioctl occurs at the same time another process is in the
process of mounting a Squashfs filesystem on /dev/loop0, the failure
occurs. When this happens the following code in squashfs_fill_super()
fails.
----
msblk->devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE);
msblk->devblksize_log2 = ffz(~msblk->devblksize);
----
sb_min_blocksize() returns 0, which means msblk->devblksize is set to 0.
As a result, ffz(~msblk->devblksize) returns 64, and msblk->devblksize_log2
is set to 64.
This subsequently causes the
UBSAN: shift-out-of-bounds in fs/squashfs/block.c:195:36
shift exponent 64 is too large for 64-bit type 'u64' (aka
'unsigned long long')
This commit adds a check for a 0 return by sb_min_blocksize().
Affected
36 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | debian_linux | — | — |
| debian | linux | < linux 6.1.147-1 (bookworm) | linux 6.1.147-1 (bookworm) |
| debian | linux-6.1 | < linux 6.1.147-1 (bookworm) | linux 6.1.147-1 (bookworm) |
| linux | linux | — | — |
| linux | linux | >= 0aa666190509ffab81c202c5095a166be23961ac < db7096ea160e40d78c67fce52e7cc51bde049497 | db7096ea160e40d78c67fce52e7cc51bde049497 |
| linux | linux | >= 0aa666190509ffab81c202c5095a166be23961ac < 549f9e3d7b60d53808c98b9fde49b4f46d0524a5 | 549f9e3d7b60d53808c98b9fde49b4f46d0524a5 |
| linux | linux | >= 0aa666190509ffab81c202c5095a166be23961ac < 5c51aa862cbeed2f3887f0382a2708956710bd68 | 5c51aa862cbeed2f3887f0382a2708956710bd68 |
| linux | linux | >= 0aa666190509ffab81c202c5095a166be23961ac < 6abf6b78c6fb112eee495f5636ffcc350dd2ce25 | 6abf6b78c6fb112eee495f5636ffcc350dd2ce25 |
| linux | linux | >= 0aa666190509ffab81c202c5095a166be23961ac < 4f99357dadbf9c979ad737156ad4c37fadf7c56b | 4f99357dadbf9c979ad737156ad4c37fadf7c56b |
| linux | linux | >= 0aa666190509ffab81c202c5095a166be23961ac < 0aff95d9bc7fb5400ca8af507429c4b067bdb425 | 0aff95d9bc7fb5400ca8af507429c4b067bdb425 |
| linux | linux | >= 0aa666190509ffab81c202c5095a166be23961ac < 295ab18c2dbce8d0ac6ecf7c5187e16e1ac8b282 | 295ab18c2dbce8d0ac6ecf7c5187e16e1ac8b282 |
| linux | linux | >= 0aa666190509ffab81c202c5095a166be23961ac < 734aa85390ea693bb7eaf2240623d41b03705c84 | 734aa85390ea693bb7eaf2240623d41b03705c84 |
| linux | linux_kernel | >= 0 < 5.10.244-1 | 5.10.244-1 |
| linux | linux_kernel | >= 0 < 6.1.147-1 | 6.1.147-1 |
| linux | linux_kernel | >= 0 < 6.12.35-1 | 6.12.35-1 |
| linux | linux_kernel | >= 0 < 6.12.35-1 | 6.12.35-1 |
| linux | linux_kernel | >= 0 < 5.15.0-156.166 | 5.15.0-156.166 |
| linux | linux_kernel | >= 0 < 6.8.0-100.100 | 6.8.0-100.100 |
| linux | linux_kernel | >= 2.6.29 < 5.4.295 | 5.4.295 |
| linux | linux_kernel | >= 5.11 < 5.15.186 | 5.15.186 |
| linux | linux_kernel | >= 5.16 < 6.1.142 | 6.1.142 |
| linux | linux_kernel | >= 5.5 < 5.10.239 | 5.10.239 |
| linux | linux_kernel | >= 6.13 < 6.15.3 | 6.15.3 |
| linux | linux_kernel | >= 6.2 < 6.6.94 | 6.6.94 |
| linux | linux_kernel | >= 6.7 < 6.12.34 | 6.12.34 |
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.8HIGH