CVE-2023-52786: In the Linux kernel, the following vulnerability has been resolved: ext4: fix racy may inline data check in dio write syzbot reports that the following warning…

PriorityP417medium4.7CVSS 3.1

AVLACHPRLUINSUCNINAH

EPSS

0.18%

7.6th percentile

In the Linux kernel, the following vulnerability has been resolved: ext4: fix racy may inline data check in dio write syzbot reports that the following warning from ext4_iomap_begin() triggers as of the commit referenced below: if (WARN_ON_ONCE(ext4_has_inline_data(inode))) return -ERANGE; This occurs during a dio write, which is never expected to encounter an inode with inline data. To enforce this behavior, ext4_dio_write_iter() checks the current inline state of the inode and clears the MAY_INLINE_DATA state flag to either fall back to buffered writes, or enforce that any other writers in progress on the inode are not allowed to create inline data. The problem is that the check for existing inline data and the state flag can span a lock cycle. For example, if the ilock is originally locked shared and subsequently upgraded to exclusive, another writer may have reacquired the lock and created inline data before the dio write task acquires the lock and proceeds. The commit referenced below loosens the lock requirements to allow some forms of unaligned dio writes to occur under shared lock, but AFAICT the inline data check was technically already racy for any dio write that would have involved a lock cycle. Regardless, lift clearing of the state bit to the same lock critical section that checks for preexisting inline data on the inode to close the race.

Affected

9 ranges

Vendor	Product	Version range	Fixed in
debian	linux	< linux 6.6.8-1 (forky)	linux 6.6.8-1 (forky)
linux	linux	—	—
linux	linux	>= 310ee0902b8d9d0a13a5a13e94688a5863fa29c2 < e3b83d87c93eb6fc96a80b5e8527f7dc9f5a11bc	e3b83d87c93eb6fc96a80b5e8527f7dc9f5a11bc
linux	linux	>= 310ee0902b8d9d0a13a5a13e94688a5863fa29c2 < 7343c23ebcadbedc23a7063d1e24d976eccb0d0d	7343c23ebcadbedc23a7063d1e24d976eccb0d0d
linux	linux	>= 310ee0902b8d9d0a13a5a13e94688a5863fa29c2 < ce56d21355cd6f6937aca32f1f44ca749d1e4808	ce56d21355cd6f6937aca32f1f44ca749d1e4808
linux	linux_kernel	>= 0 < 6.6.8-1	6.6.8-1
linux	linux_kernel	>= 0 < 6.6.8-1	6.6.8-1
linux	linux_kernel	>= 6.5 < 6.5.13	6.5.13
linux	linux_kernel	>= 6.6 < 6.6.3	6.6.3

CVSS provenance

nvdv3.14.7MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

osv4.7MEDIUM

vendor_debian4.7LOW

vendor_redhat4.7MEDIUM

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