From bf240fee5b341fbc68615f04892af274e7abf8b3 Mon Sep 17 00:00:00 2001 From: Xiao Ni Date: Fri, 28 May 2021 14:16:38 +0800 Subject: [PATCH] async_xor: check src_offs is not NULL before updating it commit 9be148e408df7d361ec5afd6299b7736ff3928b0 upstream. When PAGE_SIZE is greater than 4kB, multiple stripes may share the same page. Thus, src_offs is added to async_xor_offs() with array of offsets. However, async_xor() passes NULL src_offs to async_xor_offs(). In such case, src_offs should not be updated. Add a check before the update. Fixes: ceaf2966ab08(async_xor: increase src_offs when dropping destination page) Cc: stable@vger.kernel.org # v5.10+ Reported-by: Oleksandr Shchirskyi Tested-by: Oleksandr Shchirskyi Signed-off-by: Xiao Ni Signed-off-by: Song Liu Signed-off-by: Greg Kroah-Hartman --- crypto/async_tx/async_xor.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/crypto/async_tx/async_xor.c b/crypto/async_tx/async_xor.c index 6cd7f7025df4..d8a91521144e 100644 --- a/crypto/async_tx/async_xor.c +++ b/crypto/async_tx/async_xor.c @@ -233,7 +233,8 @@ async_xor_offs(struct page *dest, unsigned int offset, if (submit->flags & ASYNC_TX_XOR_DROP_DST) { src_cnt--; src_list++; - src_offs++; + if (src_offs) + src_offs++; } /* wait for any prerequisite operations */