| Message ID | 20210608080641.16543-1-paskripkin@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] net: rds: fix memory leak in rds_recvmsg | expand |
> On 8 Jun 2021, at 10:06, Pavel Skripkin <paskripkin@gmail.com> wrote: > > Syzbot reported memory leak in rds. The problem > was in unputted refcount in case of error. > > int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, > int msg_flags) > { > ... > > if (!rds_next_incoming(rs, &inc)) { > ... > } > > After this "if" inc refcount incremented and > > if (rds_cmsg_recv(inc, msg, rs)) { > ret = -EFAULT; > goto out; > } > ... > out: > return ret; > } > > in case of rds_cmsg_recv() fail the refcount won't be > decremented. And it's easy to see from ftrace log, that > rds_inc_addref() don't have rds_inc_put() pair in > rds_recvmsg() after rds_cmsg_recv() > > 1) | rds_recvmsg() { > 1) 3.721 us | rds_inc_addref(); > 1) 3.853 us | rds_message_inc_copy_to_user(); > 1) + 10.395 us | rds_cmsg_recv(); > 1) + 34.260 us | } > > Fixes: bdbe6fbc6a2f ("RDS: recv.c") > Reported-and-tested-by: syzbot+5134cdf021c4ed5aaa5f@syzkaller.appspotmail.com > Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com> Thanks for fixing this, Håkon > --- > > Changes in v2: > Changed goto to break. > > --- > net/rds/recv.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/rds/recv.c b/net/rds/recv.c > index 4db109fb6ec2..5b426dc3634d 100644 > --- a/net/rds/recv.c > +++ b/net/rds/recv.c > @@ -714,7 +714,7 @@ int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, > > if (rds_cmsg_recv(inc, msg, rs)) { > ret = -EFAULT; > - goto out; > + break; > } > rds_recvmsg_zcookie(rs, msg); > > -- > 2.31.1 >
On Jun 8, 2021, at 1:06 AM, Pavel Skripkin <paskripkin@gmail.com> wrote: > > Syzbot reported memory leak in rds. The problem > was in unputted refcount in case of error. > > int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, > int msg_flags) > { > ... > > if (!rds_next_incoming(rs, &inc)) { > ... > } > > After this "if" inc refcount incremented and > > if (rds_cmsg_recv(inc, msg, rs)) { > ret = -EFAULT; > goto out; > } > ... > out: > return ret; > } > > in case of rds_cmsg_recv() fail the refcount won't be > decremented. And it's easy to see from ftrace log, that > rds_inc_addref() don't have rds_inc_put() pair in > rds_recvmsg() after rds_cmsg_recv() > > 1) | rds_recvmsg() { > 1) 3.721 us | rds_inc_addref(); > 1) 3.853 us | rds_message_inc_copy_to_user(); > 1) + 10.395 us | rds_cmsg_recv(); > 1) + 34.260 us | } > > Fixes: bdbe6fbc6a2f ("RDS: recv.c") > Reported-and-tested-by: syzbot+5134cdf021c4ed5aaa5f@syzkaller.appspotmail.com > Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> > --- > > Changes in v2: > Changed goto to break. > Looks fine by me. Thanks for the fix. Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Hello: This patch was applied to netdev/net.git (refs/heads/master): On Tue, 8 Jun 2021 11:06:41 +0300 you wrote: > Syzbot reported memory leak in rds. The problem > was in unputted refcount in case of error. > > int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, > int msg_flags) > { > ... > > [...] Here is the summary with links: - [v2] net: rds: fix memory leak in rds_recvmsg https://git.kernel.org/netdev/net/c/49bfcbfd989a You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
diff --git a/net/rds/recv.c b/net/rds/recv.c index 4db109fb6ec2..5b426dc3634d 100644 --- a/net/rds/recv.c +++ b/net/rds/recv.c @@ -714,7 +714,7 @@ int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, if (rds_cmsg_recv(inc, msg, rs)) { ret = -EFAULT; - goto out; + break; } rds_recvmsg_zcookie(rs, msg);
Syzbot reported memory leak in rds. The problem was in unputted refcount in case of error. int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, int msg_flags) { ... if (!rds_next_incoming(rs, &inc)) { ... } After this "if" inc refcount incremented and if (rds_cmsg_recv(inc, msg, rs)) { ret = -EFAULT; goto out; } ... out: return ret; } in case of rds_cmsg_recv() fail the refcount won't be decremented. And it's easy to see from ftrace log, that rds_inc_addref() don't have rds_inc_put() pair in rds_recvmsg() after rds_cmsg_recv() 1) | rds_recvmsg() { 1) 3.721 us | rds_inc_addref(); 1) 3.853 us | rds_message_inc_copy_to_user(); 1) + 10.395 us | rds_cmsg_recv(); 1) + 34.260 us | } Fixes: bdbe6fbc6a2f ("RDS: recv.c") Reported-and-tested-by: syzbot+5134cdf021c4ed5aaa5f@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> --- Changes in v2: Changed goto to break. --- net/rds/recv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)