Description

In the Linux kernel, the following vulnerability has been resolved:

fs/ntfs3: Keep write operations atomic

syzbot reported a NULL pointer dereference in __generic_file_write_iter. [1]

Before the write operation is completed, the user executes ioctl[2] to clear
the compress flag of the file, which causes the is_compressed() judgment to
return 0, further causing the program to enter the wrong process and call the
wrong ops ntfs_aops_cmpr, which triggers the null pointer dereference of
write_begin.

Use inode lock to synchronize ioctl and write to avoid this case.

[1]
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Mem abort info:
ESR = 0x0000000086000006
EC = 0x21: IABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x06: level 2 translation fault
user pgtable: 4k pages, 48-bit VAs, pgdp=000000011896d000
[0000000000000000] pgd=0800000118b44403, p4d=0800000118b44403, pud=0800000117517403, pmd=0000000000000000
Internal error: Oops: 0000000086000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 UID: 0 PID: 6427 Comm: syz-executor347 Not tainted 6.13.0-rc3-syzkaller-g573067a5a685 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : 0x0
lr : generic_perform_write+0x29c/0x868 mm/filemap.c:4055
sp : ffff80009d4978a0
x29: ffff80009d4979c0 x28: dfff800000000000 x27: ffff80009d497bc8
x26: 0000000000000000 x25:...

Classification

CVE ID: CVE-2025-37806

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.02% (probability of being exploited)

EPSS Percentile: 4.25% (scored less or equal to compared to others)

EPSS Date: 2025-06-06 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2025-37806
https://git.kernel.org/stable/c/8db49e89a7f8b48ee59fa9ad32b6ed0879747df8
https://git.kernel.org/stable/c/464139e18f619aa14fb921a61721862f43421c54
https://git.kernel.org/stable/c/285cec318bf5a7a6c8ba999b2b6ec96f9a20590f

Timeline