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| author | Bryam Vargas <hexlabsecurity@proton.me> | 2026-07-17 06:27:01 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-09-07 17:22:57 +0200 |
| commit | 2cd9776fe3f2d88ec22c36d3c8ba09fbf9d5500c (patch) | |
| tree | e38edaa436756e7e3065103bf2c25a49e688df4e | |
| parent | ffd9a214a94f9928e54856f42b1cc3e33fb10e36 (diff) | |
| download | linux-2cd9776fe3f2d88ec22c36d3c8ba09fbf9d5500c.tar.gz linux-2cd9776fe3f2d88ec22c36d3c8ba09fbf9d5500c.zip | |
dm-pcache: clamp the tail kset read to the segment data region
commit becf07e2b0053027495ecd671b1f82fb2e615f68 upstream.
The tail-kset read in cache_replay(), the writeback worker and the GC
worker bounds its length by PCACHE_SEG_SIZE - seg_off, the raw segment
size rather than the data region. A tail near the segment end reads past
the segment data into the following control area.
Clamp the read to cache_seg_remain(), the data region.
Fixes: 1d57628ff95b ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/md/dm-pcache/cache_gc.c | 2 | ||||
| -rw-r--r-- | drivers/md/dm-pcache/cache_key.c | 2 | ||||
| -rw-r--r-- | drivers/md/dm-pcache/cache_writeback.c | 2 |
3 files changed, 3 insertions, 3 deletions
diff --git a/drivers/md/dm-pcache/cache_gc.c b/drivers/md/dm-pcache/cache_gc.c index be7470e0a63e..3088cfef951b 100644 --- a/drivers/md/dm-pcache/cache_gc.c +++ b/drivers/md/dm-pcache/cache_gc.c @@ -37,7 +37,7 @@ static bool need_gc(struct pcache_cache *cache, struct pcache_cache_pos *dirty_t kset_onmedia = (struct pcache_cache_kset_onmedia *)cache->gc_kset_onmedia_buf; - to_copy = min(PCACHE_KSET_ONMEDIA_SIZE_MAX, PCACHE_SEG_SIZE - key_tail->seg_off); + to_copy = min(PCACHE_KSET_ONMEDIA_SIZE_MAX, cache_seg_remain(key_tail)); ret = copy_mc_to_kernel(kset_onmedia, key_addr, to_copy); if (ret) { pcache_dev_err(pcache, "error to read kset: %d", ret); diff --git a/drivers/md/dm-pcache/cache_key.c b/drivers/md/dm-pcache/cache_key.c index fcb2c8e356b3..def81b74a181 100644 --- a/drivers/md/dm-pcache/cache_key.c +++ b/drivers/md/dm-pcache/cache_key.c @@ -779,7 +779,7 @@ int cache_replay(struct pcache_cache *cache) __set_bit(pos->cache_seg->cache_seg_id, cache->seg_map); while (true) { - to_copy = min(PCACHE_KSET_ONMEDIA_SIZE_MAX, PCACHE_SEG_SIZE - pos->seg_off); + to_copy = min(PCACHE_KSET_ONMEDIA_SIZE_MAX, cache_seg_remain(pos)); ret = copy_mc_to_kernel(kset_onmedia, cache_pos_addr(pos), to_copy); if (ret) { ret = -EIO; diff --git a/drivers/md/dm-pcache/cache_writeback.c b/drivers/md/dm-pcache/cache_writeback.c index 238c3f97e8ce..3df8687e2382 100644 --- a/drivers/md/dm-pcache/cache_writeback.c +++ b/drivers/md/dm-pcache/cache_writeback.c @@ -48,7 +48,7 @@ static inline bool is_cache_clean(struct pcache_cache *cache, struct pcache_cach addr = cache_pos_addr(dirty_tail); kset_onmedia = (struct pcache_cache_kset_onmedia *)cache->wb_kset_onmedia_buf; - to_copy = min(PCACHE_KSET_ONMEDIA_SIZE_MAX, PCACHE_SEG_SIZE - dirty_tail->seg_off); + to_copy = min(PCACHE_KSET_ONMEDIA_SIZE_MAX, cache_seg_remain(dirty_tail)); ret = copy_mc_to_kernel(kset_onmedia, addr, to_copy); if (ret) { pcache_dev_err(pcache, "error to read kset: %d", ret); |