In the Linux kernel, the following vulnerability has been resolved:
ext4: fix timer use-after-free on failed mount
Syzbot has found an ODEBUG bug in ext4_fill_super
The del_timer_sync function cancels the s_err_report timer,
which reminds about filesystem errors daily. We should
guarantee the timer is no longer active before kfree(sbi).
When filesystem mounting fails, the flow goes to failed_mount3,
where an error occurs when ext4_stop_mmpd is called, causing
a read I/O failure. This triggers the ext4_handle_error function
that ultimately re-arms the timer,
leaving the s_err_report timer active before kfree(sbi) is called.
Fix the issue by canceling the s_err_report timer after calling ext4_stop_mmpd.
CVE ID: CVE-2024-49960
Vendor: Linux
Product: Linux
EPSS Score: 0.03% (probability of being exploited)
EPSS Percentile: 6.63% (scored less or equal to compared to others)
EPSS Date: 2025-05-31 (when was this score calculated)
SSVC Exploitation: none
SSVC Technical Impact: partial
SSVC Automatable: false