github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-06-01 11:03:43 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

btrfs: check folio mapping after unlock in put_file_data()

Browse Source 
When we call btrfs_read_folio() we get an unlocked folio, so it is possible
for a different thread to concurrently modify folio->mapping. We must
check that this hasn't happened once we do have the lock.

CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Boris Burkov 2024-12-13 12:33:22 -08:00 committed by David Sterba
parent 3e74859ee3
commit 0fba7be1ca
1 changed files with 6 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
fs/btrfs/send.c
View File

@ -5280,6 +5280,7 @@ static int put_file_data(struct send_ctx *sctx, u64 offset, u32 len)
unsigned cur_len = min_t(unsigned, len,
PAGE_SIZE - pg_offset);
again:
folio = filemap_lock_folio(mapping, index);
if (IS_ERR(folio)) {
page_cache_sync_readahead(mapping,
@ -5312,6 +5313,11 @@ static int put_file_data(struct send_ctx *sctx, u64 offset, u32 len)
ret = -EIO;
break;
}
if (folio->mapping != mapping) {
folio_unlock(folio);
folio_put(folio);
goto again;
}
}
memcpy_from_folio(sctx->send_buf + sctx->send_size, folio,