[PATCH] ppp: fix out-of-bounds access in bpf_prog_create()
From: Eric Biggers <ebiggers@kernel.org>
Date: 2019-12-05 05:55:37
Also in:
bpf, linux-fsdevel, lkml
Subsystem:
networking drivers, ppp protocol drivers and compressors, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Eric Biggers <redacted>
sock_fprog_kern::len is in units of struct sock_filter, not bytes.
Fixes: 3e859adf3643 ("compat_ioctl: unify copy-in of ppp filters")
Reported-by: syzbot+eb853b51b10f1befa0b7@syzkaller.appspotmail.com
Signed-off-by: Eric Biggers <redacted>
---
drivers/net/ppp/ppp_generic.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 0cb1c2d0a8bc..3bf8a8b42983 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c@@ -564,8 +564,9 @@ static struct bpf_prog *get_filter(struct sock_fprog *uprog) return NULL; /* uprog->len is unsigned short, so no overflow here */ - fprog.len = uprog->len * sizeof(struct sock_filter); - fprog.filter = memdup_user(uprog->filter, fprog.len); + fprog.len = uprog->len; + fprog.filter = memdup_user(uprog->filter, + uprog->len * sizeof(struct sock_filter)); if (IS_ERR(fprog.filter)) return ERR_CAST(fprog.filter);
--
2.24.0