6.1-stable review patch. If anyone has any objections, please let me know.
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From: Arnd Bergmann arnd@arndb.de
commit 66ad2fbcdbeab0edfd40c5d94f32f053b98c2320 upstream.
The newly added integrity_recheck() function has another larger stack allocation, just like its caller integrity_metadata(). When it gets inlined, the combination of the two exceeds the warning limit for 32-bit architectures and possibly risks an overflow when this is called from a deep call chain through a file system:
drivers/md/dm-integrity.c:1767:13: error: stack frame size (1048) exceeds limit (1024) in 'integrity_metadata' [-Werror,-Wframe-larger-than] 1767 | static void integrity_metadata(struct work_struct *w)
Since the caller at this point is done using its checksum buffer, just reuse the same buffer in the new function to avoid the double allocation.
[Mikulas: add "noinline" to integrity_recheck and verity_recheck. These functions are only called on error, so they shouldn't bloat the stack frame or code size of the caller.]
Fixes: c88f5e553fe3 ("dm-integrity: recheck the integrity tag after a failure") Fixes: 9177f3c0dea6 ("dm-verity: recheck the hash after a failure") Cc: stable@vger.kernel.org Signed-off-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Mikulas Patocka mpatocka@redhat.com Signed-off-by: Mike Snitzer snitzer@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/dm-integrity.c | 10 ++++------ drivers/md/dm-verity-target.c | 4 ++-- 2 files changed, 6 insertions(+), 8 deletions(-)
--- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -1701,14 +1701,13 @@ failed: get_random_bytes(result, ic->tag_size); }
-static void integrity_recheck(struct dm_integrity_io *dio) +static noinline void integrity_recheck(struct dm_integrity_io *dio, char *checksum) { struct bio *bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io)); struct dm_integrity_c *ic = dio->ic; struct bvec_iter iter; struct bio_vec bv; sector_t sector, logical_sector, area, offset; - char checksum_onstack[max_t(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)]; struct page *page; void *buffer;
@@ -1744,9 +1743,8 @@ static void integrity_recheck(struct dm_ goto free_ret; }
- integrity_sector_checksum(ic, logical_sector, buffer, - checksum_onstack); - r = dm_integrity_rw_tag(ic, checksum_onstack, &dio->metadata_block, + integrity_sector_checksum(ic, logical_sector, buffer, checksum); + r = dm_integrity_rw_tag(ic, checksum, &dio->metadata_block, &dio->metadata_offset, ic->tag_size, TAG_CMP); if (r) { if (r > 0) { @@ -1859,7 +1857,7 @@ again: checksums_ptr - checksums, dio->op == REQ_OP_READ ? TAG_CMP : TAG_WRITE); if (unlikely(r)) { if (r > 0) { - integrity_recheck(dio); + integrity_recheck(dio, checksums); goto skip_io; } if (likely(checksums != checksums_onstack)) --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -483,8 +483,8 @@ static int verity_recheck_copy(struct dm return 0; }
-static int verity_recheck(struct dm_verity *v, struct dm_verity_io *io, - struct bvec_iter start, sector_t cur_block) +static noinline int verity_recheck(struct dm_verity *v, struct dm_verity_io *io, + struct bvec_iter start, sector_t cur_block) { struct page *page; void *buffer;