CVE-2024-56780

In the Linux kernel, the following vulnerability has been resolved: quota: flush quota_release_work upon quota writeback One of the paths quota writeback is called from is: freeze_super() sync_filesystem() ext4_sync_fs() dquot_writeback_dquots() Since we currently don't always flush the quota_release_work queue in this path, we can end up with the following race: 1. dquot are added to releasing_dquots list during regular operations. 2. FS Freeze starts, however, this does not flush the quota_release_work queue. 3. Freeze completes. 4. Kernel eventually tries to flush the workqueue while FS is frozen which hits a WARN_ON since transaction gets started during frozen state: ext4_journal_check_start+0x28/0x110 [ext4] (unreliable) __ext4_journal_start_sb+0x64/0x1c0 [ext4] ext4_release_dquot+0x90/0x1d0 [ext4] quota_release_workfn+0x43c/0x4d0 Which is the following line: WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE); Which ultimately results in generic/390 failing due to dmesg noise. This was detected on powerpc machine 15 cores. To avoid this, make sure to flush the workqueue during dquot_writeback_dquots() so we dont have any pending workitems after freeze.

• linux linux kernel (>= 4.19.295 < 4.20) • linux linux kernel (>= 5.4.257 < 5.4.287) • linux linux kernel (>= 5.10.195 < 5.10.231) • linux linux kernel (>= 5.15.132 < 5.15.174) • linux linux kernel (>= 6.1.53 < 6.1.120) • linux linux kernel (>= 6.4.16 < 6.5) • linux linux kernel (>= 6.5.3 < 6.6.64) • linux linux kernel (>= 6.7 < 6.12.4) • linux linux kernel 6.13