CVE-2024-49960: ext4: fix timer use-after-free on failed mount

First published: Mon Oct 21 2024(Updated: )

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 We should guarantee the timer is no longer active before kfree(sbi).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

Credit: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Never miss a vulnerability like this again

Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.

Read MoreStart Free Trial

• agent/references
• agent/title
• agent/type
• agent/description
• agent/first-publish-date
• agent/author
• agent/event
• collector/nvd-api
• source/NVD
• agent/software-canonical-lookup
• agent/remedy
• agent/severity
• agent/softwarecombine
• agent/tags
• agent/weakness
• agent/last-modified-date
• collector/mitre-cve
• source/MITRE
• vendor/linux
• canonical/linux linux kernel
• version/linux linux kernel/6.7
• version/linux linux kernel/6.11