CVE-2025-38163
Analyzed Analyzed - Analysis Complete
BaseFortify

Publication date: 2025-07-03

Last updated on: 2025-12-18

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to do sanity check on sbi->total_valid_block_count syzbot reported a f2fs bug as below: ------------[ cut here ]------------ kernel BUG at fs/f2fs/f2fs.h:2521! RIP: 0010:dec_valid_block_count+0x3b2/0x3c0 fs/f2fs/f2fs.h:2521 Call Trace: f2fs_truncate_data_blocks_range+0xc8c/0x11a0 fs/f2fs/file.c:695 truncate_dnode+0x417/0x740 fs/f2fs/node.c:973 truncate_nodes+0x3ec/0xf50 fs/f2fs/node.c:1014 f2fs_truncate_inode_blocks+0x8e3/0x1370 fs/f2fs/node.c:1197 f2fs_do_truncate_blocks+0x840/0x12b0 fs/f2fs/file.c:810 f2fs_truncate_blocks+0x10d/0x300 fs/f2fs/file.c:838 f2fs_truncate+0x417/0x720 fs/f2fs/file.c:888 f2fs_setattr+0xc4f/0x12f0 fs/f2fs/file.c:1112 notify_change+0xbca/0xe90 fs/attr.c:552 do_truncate+0x222/0x310 fs/open.c:65 handle_truncate fs/namei.c:3466 [inline] do_open fs/namei.c:3849 [inline] path_openat+0x2e4f/0x35d0 fs/namei.c:4004 do_filp_open+0x284/0x4e0 fs/namei.c:4031 do_sys_openat2+0x12b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_creat fs/open.c:1522 [inline] __se_sys_creat fs/open.c:1516 [inline] __x64_sys_creat+0x124/0x170 fs/open.c:1516 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 The reason is: in fuzzed image, sbi->total_valid_block_count is inconsistent w/ mapped blocks indexed by inode, so, we should not trigger panic for such case, instead, let's print log and set fsck flag.
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2025-07-03
Last Modified
2025-12-18
Generated
2026-05-07
AI Q&A
2025-07-03
EPSS Evaluated
2026-05-05
NVD
CVE-2025-38163
Affected Vendors & Products
Showing 8 associated CPEs
Vendor Product Version / Range
linux linux_kernel From 3.8 (inc) to 5.4.295 (exc)
linux linux_kernel From 5.5 (inc) to 5.10.239 (exc)
linux linux_kernel From 5.11 (inc) to 5.15.186 (exc)
linux linux_kernel From 5.16 (inc) to 6.1.142 (exc)
linux linux_kernel From 6.2 (inc) to 6.6.94 (exc)
linux linux_kernel From 6.7 (inc) to 6.12.34 (exc)
linux linux_kernel From 6.13 (inc) to 6.15.3 (exc)
debian debian_linux 11.0
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-476 The product dereferences a pointer that it expects to be valid but is NULL.
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is in the Linux kernel's f2fs filesystem. It involves an inconsistency in the total_valid_block_count field, which tracks valid blocks. When this count is inconsistent with the blocks mapped by an inode, it previously caused a kernel panic (crash). The fix changes this behavior to avoid panic by logging the issue and setting a filesystem check (fsck) flag instead.


How can this vulnerability impact me? :

The vulnerability can cause the Linux kernel to panic (crash) when the total_valid_block_count is inconsistent, potentially leading to system instability or downtime. The fix prevents this panic, improving system reliability by logging the inconsistency and marking the filesystem for checking rather than crashing.


How can this vulnerability be detected on my network or system? Can you suggest some commands?

This vulnerability can be detected by monitoring kernel logs for the specific bug message related to f2fs, such as a kernel BUG at fs/f2fs/f2fs.h:2521 and messages involving dec_valid_block_count. You can check the kernel log using commands like 'dmesg | grep f2fs' or 'journalctl -k | grep f2fs' to look for these error messages indicating the issue.


What immediate steps should I take to mitigate this vulnerability?

Immediate mitigation steps include updating the Linux kernel to a version where this f2fs vulnerability is fixed. Additionally, monitoring logs for the bug message and running filesystem checks (fsck) on f2fs partitions to detect and repair inconsistencies can help prevent triggering kernel panic.


Ask Our AI Assistant
Need more information? Ask your question to get an AI reply (Powered by our expertise)
0/70
EPSS Chart