6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx> [ 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> --- fs/erofs/decompressor.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) 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; } -- 2.43.0
