CVE-2024-37078

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> nilfs2: fix potential kernel bug due to lack of writeback flag waiting<br /> <br /> Destructive writes to a block device on which nilfs2 is mounted can cause<br /> a kernel bug in the folio/page writeback start routine or writeback end<br /> routine (__folio_start_writeback in the log below):<br /> <br /> kernel BUG at mm/page-writeback.c:3070!<br /> Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI<br /> ...<br /> RIP: 0010:__folio_start_writeback+0xbaa/0x10e0<br /> Code: 25 ff 0f 00 00 0f 84 18 01 00 00 e8 40 ca c6 ff e9 17 f6 ff ff<br /> e8 36 ca c6 ff 4c 89 f7 48 c7 c6 80 c0 12 84 e8 e7 b3 0f 00 90 <br /> 0b e8 1f ca c6 ff 4c 89 f7 48 c7 c6 a0 c6 12 84 e8 d0 b3 0f 00<br /> ...<br /> Call Trace:<br /> <br /> nilfs_segctor_do_construct+0x4654/0x69d0 [nilfs2]<br /> nilfs_segctor_construct+0x181/0x6b0 [nilfs2]<br /> nilfs_segctor_thread+0x548/0x11c0 [nilfs2]<br /> kthread+0x2f0/0x390<br /> ret_from_fork+0x4b/0x80<br /> ret_from_fork_asm+0x1a/0x30<br /> <br /> <br /> This is because when the log writer starts a writeback for segment summary<br /> blocks or a super root block that use the backing device&amp;#39;s page cache, it<br /> does not wait for the ongoing folio/page writeback, resulting in an<br /> inconsistent writeback state.<br /> <br /> Fix this issue by waiting for ongoing writebacks when putting<br /> folios/pages on the backing device into writeback state.