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| author | Eric Biggers <ebiggers@google.com> | 2019-12-04 21:54:19 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-12-05 14:45:19 -0800 |
| commit | 0033b34a03ec5cf747cdaf9b1f9dceb91c020f17 (patch) | |
| tree | 299f3f47c09c1e21245194204662b96bb73ef6a1 /drivers/net/ppp | |
| parent | a116f4e238cc20dfbac30c65949752798f5b6efa (diff) | |
| download | lwn-0033b34a03ec5cf747cdaf9b1f9dceb91c020f17.tar.gz lwn-0033b34a03ec5cf747cdaf9b1f9dceb91c020f17.zip | |
ppp: fix out-of-bounds access in bpf_prog_create()
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 <ebiggers@google.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ppp')
| -rw-r--r-- | drivers/net/ppp/ppp_generic.c | 5 |
1 files 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); |