From: Chengming Zhou <zhouchengming@bytedance.com> mainline inclusion category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I8ZBUC CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- 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: Felix Fu <fuzhen5@huawei.com> --- crypto/scompress.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/crypto/scompress.c b/crypto/scompress.c index 968bbcf65c94..3ade31df4f22 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, @@ -176,6 +179,9 @@ static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir) req->dst = sgl_alloc(req->dlen, GFP_ATOMIC, NULL); if (!req->dst) goto out; + } else if (req->dlen > dlen) { + ret = -ENOSPC; + goto out; } scatterwalk_map_and_copy(scratch_dst, req->dst, 0, req->dlen, 1); -- 2.34.1