This is a note to let you know that I've just added the patch titled net/sctp: terminate rhashtable walk correctly to the 4.7-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-sctp-terminate-rhashtable-walk-correctly.patch and it can be found in the queue-4.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Fri Aug 12 09:34:44 CEST 2016 From: Vegard Nossum <vegard.nossum@xxxxxxxxxx> Date: Sat, 23 Jul 2016 09:42:35 +0200 Subject: net/sctp: terminate rhashtable walk correctly From: Vegard Nossum <vegard.nossum@xxxxxxxxxx> [ Upstream commit 5fc382d87517707ad77ea4c9c12e2a3fde2c838a ] I was seeing a lot of these: BUG: sleeping function called from invalid context at mm/slab.h:388 in_atomic(): 0, irqs_disabled(): 0, pid: 14971, name: trinity-c2 Preemption disabled at:[<ffffffff819bcd46>] rhashtable_walk_start+0x46/0x150 [<ffffffff81149abb>] preempt_count_add+0x1fb/0x280 [<ffffffff83295722>] _raw_spin_lock+0x12/0x40 [<ffffffff811aac87>] console_unlock+0x2f7/0x930 [<ffffffff811ab5bb>] vprintk_emit+0x2fb/0x520 [<ffffffff811aba6a>] vprintk_default+0x1a/0x20 [<ffffffff812c171a>] printk+0x94/0xb0 [<ffffffff811d6ed0>] print_stack_trace+0xe0/0x170 [<ffffffff8115835e>] ___might_sleep+0x3be/0x460 [<ffffffff81158490>] __might_sleep+0x90/0x1a0 [<ffffffff8139b823>] kmem_cache_alloc+0x153/0x1e0 [<ffffffff819bca1e>] rhashtable_walk_init+0xfe/0x2d0 [<ffffffff82ec64de>] sctp_transport_walk_start+0x1e/0x60 [<ffffffff82edd8ad>] sctp_transport_seq_start+0x4d/0x150 [<ffffffff8143a82b>] seq_read+0x27b/0x1180 [<ffffffff814f97fc>] proc_reg_read+0xbc/0x180 [<ffffffff813d471b>] __vfs_read+0xdb/0x610 [<ffffffff813d4d3a>] vfs_read+0xea/0x2d0 [<ffffffff813d615b>] SyS_pread64+0x11b/0x150 [<ffffffff8100334c>] do_syscall_64+0x19c/0x410 [<ffffffff832960a5>] return_from_SYSCALL_64+0x0/0x6a [<ffffffffffffffff>] 0xffffffffffffffff Apparently we always need to call rhashtable_walk_stop(), even when rhashtable_walk_start() fails: * rhashtable_walk_start - Start a hash table walk * @iter: Hash table iterator * * Start a hash table walk. Note that we take the RCU lock in all * cases including when we return an error. So you must always call * rhashtable_walk_stop to clean up. otherwise we never call rcu_read_unlock() and we get the splat above. Fixes: 53fa1036 ("sctp: fix some rhashtable functions using in sctp proc/diag") See-also: 53fa1036 ("sctp: fix some rhashtable functions using in sctp proc/diag") See-also: f2dba9c6 ("rhashtable: Introduce rhashtable_walk_*") Cc: Xin Long <lucien.xin@xxxxxxxxx> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Vegard Nossum <vegard.nossum@xxxxxxxxxx> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/sctp/socket.c | 1 + 1 file changed, 1 insertion(+) --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -4301,6 +4301,7 @@ int sctp_transport_walk_start(struct rha err = rhashtable_walk_start(iter); if (err && err != -EAGAIN) { + rhashtable_walk_stop(iter); rhashtable_walk_exit(iter); return err; } Patches currently in stable-queue which might be from vegard.nossum@xxxxxxxxxx are queue-4.7/ext4-verify-extent-header-depth.patch queue-4.7/net-irda-fix-null-pointer-dereference-on-memory-allocation-failure.patch queue-4.7/net-sctp-terminate-rhashtable-walk-correctly.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html