This is a note to let you know that I've just added the patch titled
erofs: avoid debugging output for (de)compressed data
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
erofs-avoid-debugging-output-for-de-compressed-data.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9b7b5305ec050bcf10976bde07b754ab03d7f3a9
Author: Gao Xiang <xiang@xxxxxxxxxx>
Date: Wed Dec 27 23:19:03 2023 +0800
erofs: avoid debugging output for (de)compressed data
[ Upstream commit 496530c7c1dfc159d59a75ae00b572f570710c53 ]
Syzbot reported a KMSAN warning,
erofs: (device loop0): z_erofs_lz4_decompress_mem: failed to decompress -12 in[46, 4050] out[917]
=====================================================
BUG: KMSAN: uninit-value in hex_dump_to_buffer+0xae9/0x10f0 lib/hexdump.c:194
..
print_hex_dump+0x13d/0x3e0 lib/hexdump.c:276
z_erofs_lz4_decompress_mem fs/erofs/decompressor.c:252 [inline]
z_erofs_lz4_decompress+0x257e/0x2a70 fs/erofs/decompressor.c:311
z_erofs_decompress_pcluster fs/erofs/zdata.c:1290 [inline]
z_erofs_decompress_queue+0x338c/0x6460 fs/erofs/zdata.c:1372
z_erofs_runqueue+0x36cd/0x3830
z_erofs_read_folio+0x435/0x810 fs/erofs/zdata.c:1843
The root cause is that the printed decompressed buffer may be filled
incompletely due to decompression failure. Since they were once only
used for debugging, get rid of them now.
Reported-and-tested-by: syzbot+6c746eea496f34b3161d@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://lore.kernel.org/r/000000000000321c24060d7cfa1c@xxxxxxxxxx
Reviewed-by: Yue Hu <huyue2@xxxxxxxxxxx>
Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20231227151903.2900413-1-hsiangkao@xxxxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index d36b3963c0bf3..aa59788a61e6e 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -248,15 +248,9 @@ static int z_erofs_lz4_decompress_mem(struct z_erofs_lz4_decompress_ctx *ctx,
if (ret != rq->outputsize) {
erofs_err(rq->sb, "failed to decompress %d in[%u, %u] out[%u]",
ret, rq->inputsize, inputmargin, rq->outputsize);
-
- print_hex_dump(KERN_DEBUG, "[ in]: ", DUMP_PREFIX_OFFSET,
- 16, 1, src + inputmargin, rq->inputsize, true);
- print_hex_dump(KERN_DEBUG, "[out]: ", DUMP_PREFIX_OFFSET,
- 16, 1, out, rq->outputsize, true);
-
if (ret >= 0)
memset(out + ret, 0, rq->outputsize - ret);
- ret = -EIO;
+ ret = -EFSCORRUPTED;
} else {
ret = 0;
}
