5.4-stable review patch. If anyone has any objections, please let me know.
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From: Nikita Zhandarovich n.zhandarovich@fintech.ru
commit 47f268f33dff4a5e31541a990dc09f116f80e61c upstream.
The result of multiplication between values derived from functions dir_buckets() and bucket_blocks() *could* technically reach 2^30 * 2^2 = 2^32.
While unlikely to happen, it is prudent to ensure that it will not lead to integer overflow. Thus, use mul_u32_u32() as it's more appropriate to mitigate the issue.
Found by Linux Verification Center (linuxtesting.org) with static analysis tool SVACE.
Fixes: 3843154598a0 ("f2fs: introduce large directory support") Cc: stable@vger.kernel.org Signed-off-by: Nikita Zhandarovich n.zhandarovich@fintech.ru Reviewed-by: Chao Yu chao@kernel.org Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/f2fs/dir.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -77,7 +77,8 @@ static unsigned long dir_block_index(uns unsigned long bidx = 0;
for (i = 0; i < level; i++) - bidx += dir_buckets(i, dir_level) * bucket_blocks(i); + bidx += mul_u32_u32(dir_buckets(i, dir_level), + bucket_blocks(i)); bidx += idx * bucket_blocks(level); return bidx; }