Description

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

ocfs2: fix DIO failure due to insufficient transaction credits

The code in ocfs2_dio_end_io_write() estimates number of necessary
transaction credits using ocfs2_calc_extend_credits(). This however does
not take into account that the IO could be arbitrarily large and can
contain arbitrary number of extents.

Extent tree manipulations do often extend the current transaction but not
in all of the cases. For example if we have only single block extents in
the tree, ocfs2_mark_extent_written() will end up calling
ocfs2_replace_extent_rec() all the time and we will never extend the
current transaction and eventually exhaust all the transaction credits if
the IO contains many single block extents. Once that happens a
WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in
jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to
this error. This was actually triggered by one of our customers on a
heavily fragmented OCFS2 filesystem.

To fix the issue make sure the transaction always has enough credits for
one extent insert before each call of ocfs2_mark_extent_written().

Heming Zhao said:

------
PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error"

PID: xxx TASK: xxxx CPU: 5 COMMAND: "SubmitThread-CA"
#0 machine_kexec at ffffffff8c069932
#1 __crash_kexec at ffffffff8c1338fa
#2 panic at ffffffff8c1d69b9
#3 ocfs2_handle_error at ffffffffc0...

Classification

CVE ID: CVE-2024-42077

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 5.08% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

https://git.kernel.org/stable/c/a68b896aa56e435506453ec8835bc991ec3ae687
https://git.kernel.org/stable/c/320273b5649bbcee87f9e65343077189699d2a7a
https://git.kernel.org/stable/c/9ea2d1c6789722d58ec191f14f9a02518d55b6b4
https://git.kernel.org/stable/c/c05ffb693bfb42a48ef3ee88a55b57392984e111
https://git.kernel.org/stable/c/331d1079d58206ff7dc5518185f800b412f89bc6
https://git.kernel.org/stable/c/be346c1a6eeb49d8fda827d2a9522124c2f72f36

Timeline