dm-pcache: reject a kset that overruns its segment

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cache_replay(), the writeback worker and the GC worker read a kset of
get_kset_onmedia_size() bytes and advance the position by it. A forged
key_num makes that size exceed the segment's remaining space, so the
advance walks past the segment and trips the cache_pos_advance() BUG_ON.

Reject a kset whose on-media size exceeds cache_seg_remain() before use.

Fixes: 1d57628ff9 ("dm-pcache: add persistent cache target in device-mapper")
Cc: stable@vger.kernel.org
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

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Bryam Vargas 2026-07-17 06:26:58 -05:00 • committed by Mikulas Patocka

parent d189857609

commit 7ac1f10f98

3 changed files with 15 additions and 0 deletions

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5

drivers/md/dm-pcache/cache_gc.c

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5

drivers/md/dm-pcache/cache_key.c

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5

drivers/md/dm-pcache/cache_writeback.c

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