CVE-2024-49960

Summary

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 We should guarantee the timer is no longer active before kfree(sbi).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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux5e4f5138bd8522ebe231a137682d3857209a2c07 < 7aac0c17a8cdf4a3236991c1e60435c6a984076caffected
LinuxLinux618f003199c6188e01472b03cdbba227f1dc5f24 < 22e9b83f0f33bc5a7a3181769d1dccbf021f5b04affected
LinuxLinux618f003199c6188e01472b03cdbba227f1dc5f24 < cf3196e5e2f36cd80dab91ffae402e13935724bcaffected
LinuxLinux618f003199c6188e01472b03cdbba227f1dc5f24 < 9203817ba46ebba7c865c8de2aba399537b6e891affected
LinuxLinux618f003199c6188e01472b03cdbba227f1dc5f24 < fa78fb51d396f4f2f80f8e96a3b1516f394258beaffected
LinuxLinux618f003199c6188e01472b03cdbba227f1dc5f24 < b85569585d0154d4db1e4f9e3e6a4731d407feb0affected
LinuxLinux618f003199c6188e01472b03cdbba227f1dc5f24 < 0ce160c5bdb67081a62293028dc85758a8efb22aaffected
LinuxLinuxcecfdb9cf9a700d1037066173abac0617f6788dfaffected
LinuxLinuxeb7b40d9d3785f7a131fb0b1f89bb6efa46c1833affected
LinuxLinux5.10.51 < 5.10.237affected
LinuxLinux5.12.18 < 5.13affected
LinuxLinux5.13.3 < 5.14affected
LinuxLinux5.14affected
LinuxLinux0 < 5.14unaffected
LinuxLinux5.10.237 <= 5.10.*unaffected
LinuxLinux5.15.181 <= 5.15.*unaffected
LinuxLinux6.1.118 <= 6.1.*unaffected
LinuxLinux6.6.55 <= 6.6.*unaffected
LinuxLinux6.10.14 <= 6.10.*unaffected
LinuxLinux6.11.3 <= 6.11.*unaffected
LinuxLinux6.12 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

CVE Program Container

Additional References

References