CVE-2023-54068
In the Linux kernel, the following vulnerability has been resolved: f2fs: compress: fix to call f2fs_wait_on_page_writeback() in f2fs_write_raw_pages() BUG_ON() will be triggered when writing files concurrently, because the same page is writtenback…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.15%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In the Linux kernel, the following vulnerability has been resolved: f2fs: compress: fix to call f2fs_wait_on_page_writeback() in f2fs_write_raw_pages() BUG_ON() will be triggered when writing files concurrently, because the same page is writtenback multiple times. 1597 void folio_end_writeback(struct folio *folio) 1598 { ...... 1618 if (!__folio_end_writeback(folio)) 1619 BUG(); ...... 1625 } kernel BUG at mm/filemap.c:1619! Call Trace: <TASK> f2fs_write_end_io+0x1a0/0x370 blk_update_request+0x6c/0x410 blk_mq_end_request+0x15/0x130 blk_complete_reqs+0x3c/0x50 __do_softirq+0xb8/0x29b ? sort_range+0x20/0x20 run_ksoftirqd+0x19/0x20 smpboot_thread_fn+0x10b/0x1d0 kthread+0xde/0x110 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x22/0x30 </TASK> Below is the concurrency scenario: [Process A] [Process B] [Process C] f2fs_write_raw_pages() - redirty_page_for_writepage() - unlock page() f2fs_do_write_data_page() - lock_page() - clear_page_dirty_for_io() - set_page_writeback() [1st writeback] ..... - unlock page() generic_perform_write() - f2fs_write_begin() - wait_for_stable_page() - f2fs_write_end() - set_page_dirty() - lock_page() - f2fs_do_write_data_page() - set_page_writeback() [2st writeback] This problem was introduced by the previous commit 7377e853967b ("f2fs: compress: fix potential deadlock of compress file"). All pagelocks were released in f2fs_write_raw_pages(), but whether the page was in the writeback state was ignored in the subsequent writing process. Let's fix it by waiting for the page to writeback before writing.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.15% probability · 5th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/169134da419cb8ffbe3b0743bc24573e16952ea9
- https://git.kernel.org/stable/c/6604df2a9d07ba8f8fb1ac14046c2c83776faa4f
- https://git.kernel.org/stable/c/9940877c4fe752923a53f0f7372f2f152b6eccf0
- https://git.kernel.org/stable/c/a8226a45b2a9ce83ba7a167a387a00fecc319e71
- https://git.kernel.org/stable/c/ad31eed06c3b4d63b2d38322a271d4009aee4bb3
- https://git.kernel.org/stable/c/babedcbac164cec970872b8097401ca913a80e61
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.