Re: crypto: deadlock between crypto_alg_sem/rtnl_mutex/genl_mutex

[Herbert Xu]

On Sun, Mar 05, 2017 at 06:36:12PM +0100, Dmitry Vyukov wrote:
>
> > -> #1 (genl_mutex){+.+.+.}:
> >        validate_chain kernel/locking/lockdep.c:2267 [inline]
> >        __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340
> >        lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755
> >        __mutex_lock_common kernel/locking/mutex.c:756 [inline]
> >        __mutex_lock+0x172/0x1730 kernel/locking/mutex.c:893
> >        mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
> >        genl_lock net/netlink/genetlink.c:32 [inline]
> >        genl_lock_dumpit+0x41/0x90 net/netlink/genetlink.c:478
> >        netlink_dump+0x54d/0xd40 net/netlink/af_netlink.c:2127
> >        __netlink_dump_start+0x4e5/0x760 net/netlink/af_netlink.c:2217
> >        genl_family_rcv_msg+0xd9d/0x1040 net/netlink/genetlink.c:546
> >        genl_rcv_msg+0xa6/0x140 net/netlink/genetlink.c:620
> >        netlink_rcv_skb+0x2ab/0x390 net/netlink/af_netlink.c:2298
> >        genl_rcv+0x28/0x40 net/netlink/genetlink.c:631
> >        netlink_unicast_kernel net/netlink/af_netlink.c:1231 [inline]
> >        netlink_unicast+0x514/0x730 net/netlink/af_netlink.c:1257
> >        netlink_sendmsg+0xa9f/0xe50 net/netlink/af_netlink.c:1803
> >        sock_sendmsg_nosec net/socket.c:633 [inline]
> >        sock_sendmsg+0xca/0x110 net/socket.c:643
> >        sock_write_iter+0x326/0x600 net/socket.c:846
> >        call_write_iter include/linux/fs.h:1733 [inline]
> >        new_sync_write fs/read_write.c:497 [inline]
> >        __vfs_write+0x483/0x740 fs/read_write.c:510
> >        vfs_write+0x187/0x530 fs/read_write.c:558
> >        SYSC_write fs/read_write.c:605 [inline]
> >        SyS_write+0xfb/0x230 fs/read_write.c:597
> >        entry_SYSCALL_64_fastpath+0x1f/0xc2
> >
> > -> #0 (nlk->cb_mutex){+.+.+.}:
> >        check_prev_add kernel/locking/lockdep.c:1830 [inline]
> >        check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940
> >        validate_chain kernel/locking/lockdep.c:2267 [inline]
> >        __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340
> >        lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755
> >        __mutex_lock_common kernel/locking/mutex.c:756 [inline]
> >        __mutex_lock+0x172/0x1730 kernel/locking/mutex.c:893
> >        mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
> >        __netlink_dump_start+0xf4/0x760 net/netlink/af_netlink.c:2187
> >        netlink_dump_start include/linux/netlink.h:165 [inline]
> >        crypto_user_rcv_msg+0x2ad/0x4f0 crypto/crypto_user.c:517
> >        netlink_rcv_skb+0x2ab/0x390 net/netlink/af_netlink.c:2298
> >        crypto_netlink_rcv+0x2a/0x40 crypto/crypto_user.c:538
> >        netlink_unicast_kernel net/netlink/af_netlink.c:1231 [inline]
> >        netlink_unicast+0x514/0x730 net/netlink/af_netlink.c:1257
> >        netlink_sendmsg+0xa9f/0xe50 net/netlink/af_netlink.c:1803
> >        sock_sendmsg_nosec net/socket.c:633 [inline]
> >        sock_sendmsg+0xca/0x110 net/socket.c:643
> >        ___sys_sendmsg+0x8fa/0x9f0 net/socket.c:1985
> >        __sys_sendmsg+0x138/0x300 net/socket.c:2019
> >        SYSC_sendmsg net/socket.c:2030 [inline]
> >        SyS_sendmsg+0x2d/0x50 net/socket.c:2026
> >        entry_SYSCALL_64_fastpath+0x1f/0xc2

Ditto.  Please disregard any reports involving genl_mutex and
cb_mutex where the latter comes from crypto_user.

Thanks,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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