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| author | Eric Dumazet <edumazet@google.com> | 2018-04-29 18:55:20 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-05-01 12:25:58 -0400 |
| commit | bf2acc943a45d2b2e8a9f1a5ddff6b6e43cc69d9 (patch) | |
| tree | aabf5c5b86d2489b821627f90fad5068e002b1aa | |
| parent | cea67a2dd6b2419dcc13a39309b9a79a1f773193 (diff) | |
| download | linux-bf2acc943a45d2b2e8a9f1a5ddff6b6e43cc69d9.tar.bz2 | |
tcp: fix TCP_REPAIR_QUEUE bound checking
syzbot is able to produce a nasty WARN_ON() in tcp_verify_left_out()
with following C-repro :
socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 3
setsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0
setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [-1], 4) = 0
bind(3, {sa_family=AF_INET, sin_port=htons(20002), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
sendto(3, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"...,
1242, MSG_FASTOPEN, {sa_family=AF_INET, sin_port=htons(20002), sin_addr=inet_addr("127.0.0.1")}, 16) = 1242
setsockopt(3, SOL_TCP, TCP_REPAIR_WINDOW, "\4\0\0@+\205\0\0\377\377\0\0\377\377\377\177\0\0\0\0", 20) = 0
writev(3, [{"\270", 1}], 1) = 1
setsockopt(3, SOL_TCP, TCP_REPAIR_OPTIONS, "\10\0\0\0\0\0\0\0\0\0\0\0|\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 386) = 0
writev(3, [{"\210v\r[\226\320t\231qwQ\204\264l\254\t\1\20\245\214p\350H\223\254;\\\37\345\307p$"..., 3144}], 1) = 3144
The 3rd system call looks odd :
setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [-1], 4) = 0
This patch makes sure bound checking is using an unsigned compare.
Fixes: ee9952831cfd ("tcp: Initial repair mode")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/tcp.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 4b18ad41d4df..44be7f43455e 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2674,7 +2674,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level, case TCP_REPAIR_QUEUE: if (!tp->repair) err = -EPERM; - else if (val < TCP_QUEUES_NR) + else if ((unsigned int)val < TCP_QUEUES_NR) tp->repair_queue = val; else err = -EINVAL; |