From: Chengming Zhou zhouchengming@bytedance.com

stable inclusion from stable-v4.19.306 commit 1142d65c5b881590962ad763f94505b6dd67d2fe category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I970CO CVE: NA

Reference: https://github.com/gregkh/linux/commit/1142d65c5b881590962ad763f94505b6dd67d...

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[ Upstream commit 744e1885922a9943458954cfea917b31064b4131 ]

The req->dst buffer size should be checked before copying from the scomp_scratch->dst to avoid req->dst buffer overflow problem.

Fixes: 1ab53a77b772 ("crypto: acomp - add driver-side scomp interface") Reported-by: syzbot+3eff5e51bf1db122a16e@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/0000000000000b05cd060d6b5511@google.com/ Signed-off-by: Chengming Zhou zhouchengming@bytedance.com Reviewed-by: Barry Song v-songbaohua@oppo.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org Conflicts: crypto/scompress.c Signed-off-by: GUO Zihua guozihua@huawei.com --- crypto/scompress.c | 6 ++++++ 1 file changed, 6 insertions(+)

diff --git a/crypto/scompress.c b/crypto/scompress.c index 15641c96ff99..5f3fb6cbf531 100644 --- a/crypto/scompress.c +++ b/crypto/scompress.c @@ -149,6 +149,7 @@ static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir) const int cpu = get_cpu(); u8 *scratch_src = *per_cpu_ptr(scomp_src_scratches, cpu); u8 *scratch_dst = *per_cpu_ptr(scomp_dst_scratches, cpu); + unsigned int dlen; int ret;

if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE) { @@ -164,6 +165,8 @@ static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir) if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE) req->dlen = SCOMP_SCRATCH_SIZE;

+ dlen = req->dlen; + scatterwalk_map_and_copy(scratch_src, req->src, 0, req->slen, 0); if (dir) ret = crypto_scomp_compress(scomp, scratch_src, req->slen, @@ -178,6 +181,9 @@ static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir) ret = -ENOMEM; goto out; } + } else if (req->dlen > dlen) { + ret = -ENOSPC; + goto out; } scatterwalk_map_and_copy(scratch_dst, req->dst, 0, req->dlen, 1);