Patch "netrom: fix possible dead-lock in nr_rt_ioctl()" has been added to the 5.15-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This is a note to let you know that I've just added the patch titled

    netrom: fix possible dead-lock in nr_rt_ioctl()

to the 5.15-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:
     netrom-fix-possible-dead-lock-in-nr_rt_ioctl.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 13714b594c28e20e6ecad8351778cdf64161019d
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date:   Wed May 15 14:29:34 2024 +0000

    netrom: fix possible dead-lock in nr_rt_ioctl()
    
    [ Upstream commit e03e7f20ebf7e1611d40d1fdc1bde900fd3335f6 ]
    
    syzbot loves netrom, and found a possible deadlock in nr_rt_ioctl [1]
    
    Make sure we always acquire nr_node_list_lock before nr_node_lock(nr_node)
    
    [1]
    WARNING: possible circular locking dependency detected
    6.9.0-rc7-syzkaller-02147-g654de42f3fc6 #0 Not tainted
    ------------------------------------------------------
    syz-executor350/5129 is trying to acquire lock:
     ffff8880186e2070 (&nr_node->node_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
     ffff8880186e2070 (&nr_node->node_lock){+...}-{2:2}, at: nr_node_lock include/net/netrom.h:152 [inline]
     ffff8880186e2070 (&nr_node->node_lock){+...}-{2:2}, at: nr_dec_obs net/netrom/nr_route.c:464 [inline]
     ffff8880186e2070 (&nr_node->node_lock){+...}-{2:2}, at: nr_rt_ioctl+0x1bb/0x1090 net/netrom/nr_route.c:697
    
    but task is already holding lock:
     ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
     ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: nr_dec_obs net/netrom/nr_route.c:462 [inline]
     ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: nr_rt_ioctl+0x10a/0x1090 net/netrom/nr_route.c:697
    
    which lock already depends on the new lock.
    
    the existing dependency chain (in reverse order) is:
    
    -> #1 (nr_node_list_lock){+...}-{2:2}:
            lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
            __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
            _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
            spin_lock_bh include/linux/spinlock.h:356 [inline]
            nr_remove_node net/netrom/nr_route.c:299 [inline]
            nr_del_node+0x4b4/0x820 net/netrom/nr_route.c:355
            nr_rt_ioctl+0xa95/0x1090 net/netrom/nr_route.c:683
            sock_do_ioctl+0x158/0x460 net/socket.c:1222
            sock_ioctl+0x629/0x8e0 net/socket.c:1341
            vfs_ioctl fs/ioctl.c:51 [inline]
            __do_sys_ioctl fs/ioctl.c:904 [inline]
            __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890
            do_syscall_x64 arch/x86/entry/common.c:52 [inline]
            do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
           entry_SYSCALL_64_after_hwframe+0x77/0x7f
    
    -> #0 (&nr_node->node_lock){+...}-{2:2}:
            check_prev_add kernel/locking/lockdep.c:3134 [inline]
            check_prevs_add kernel/locking/lockdep.c:3253 [inline]
            validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
            __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
            lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
            __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
            _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
            spin_lock_bh include/linux/spinlock.h:356 [inline]
            nr_node_lock include/net/netrom.h:152 [inline]
            nr_dec_obs net/netrom/nr_route.c:464 [inline]
            nr_rt_ioctl+0x1bb/0x1090 net/netrom/nr_route.c:697
            sock_do_ioctl+0x158/0x460 net/socket.c:1222
            sock_ioctl+0x629/0x8e0 net/socket.c:1341
            vfs_ioctl fs/ioctl.c:51 [inline]
            __do_sys_ioctl fs/ioctl.c:904 [inline]
            __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890
            do_syscall_x64 arch/x86/entry/common.c:52 [inline]
            do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
           entry_SYSCALL_64_after_hwframe+0x77/0x7f
    
    other info that might help us debug this:
    
     Possible unsafe locking scenario:
    
           CPU0                    CPU1
           ----                    ----
      lock(nr_node_list_lock);
                                   lock(&nr_node->node_lock);
                                   lock(nr_node_list_lock);
      lock(&nr_node->node_lock);
    
     *** DEADLOCK ***
    
    1 lock held by syz-executor350/5129:
      #0: ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
      #0: ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: nr_dec_obs net/netrom/nr_route.c:462 [inline]
      #0: ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: nr_rt_ioctl+0x10a/0x1090 net/netrom/nr_route.c:697
    
    stack backtrace:
    CPU: 0 PID: 5129 Comm: syz-executor350 Not tainted 6.9.0-rc7-syzkaller-02147-g654de42f3fc6 #0
    Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
    Call Trace:
     <TASK>
      __dump_stack lib/dump_stack.c:88 [inline]
      dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
      check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
      check_prev_add kernel/locking/lockdep.c:3134 [inline]
      check_prevs_add kernel/locking/lockdep.c:3253 [inline]
      validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
      __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
      lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
      __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
      _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
      spin_lock_bh include/linux/spinlock.h:356 [inline]
      nr_node_lock include/net/netrom.h:152 [inline]
      nr_dec_obs net/netrom/nr_route.c:464 [inline]
      nr_rt_ioctl+0x1bb/0x1090 net/netrom/nr_route.c:697
      sock_do_ioctl+0x158/0x460 net/socket.c:1222
      sock_ioctl+0x629/0x8e0 net/socket.c:1341
      vfs_ioctl fs/ioctl.c:51 [inline]
      __do_sys_ioctl fs/ioctl.c:904 [inline]
      __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890
      do_syscall_x64 arch/x86/entry/common.c:52 [inline]
      do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
    
    Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
    Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
    Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
    Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240515142934.3708038-1-edumazet@xxxxxxxxxx
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/netrom/nr_route.c b/net/netrom/nr_route.c
index 983c5ad9724f1..dc39ae20c6aa6 100644
--- a/net/netrom/nr_route.c
+++ b/net/netrom/nr_route.c
@@ -285,22 +285,14 @@ static int __must_check nr_add_node(ax25_address *nr, const char *mnemonic,
 	return 0;
 }
 
-static inline void __nr_remove_node(struct nr_node *nr_node)
+static void nr_remove_node_locked(struct nr_node *nr_node)
 {
+	lockdep_assert_held(&nr_node_list_lock);
+
 	hlist_del_init(&nr_node->node_node);
 	nr_node_put(nr_node);
 }
 
-#define nr_remove_node_locked(__node) \
-	__nr_remove_node(__node)
-
-static void nr_remove_node(struct nr_node *nr_node)
-{
-	spin_lock_bh(&nr_node_list_lock);
-	__nr_remove_node(nr_node);
-	spin_unlock_bh(&nr_node_list_lock);
-}
-
 static inline void __nr_remove_neigh(struct nr_neigh *nr_neigh)
 {
 	hlist_del_init(&nr_neigh->neigh_node);
@@ -339,6 +331,7 @@ static int nr_del_node(ax25_address *callsign, ax25_address *neighbour, struct n
 		return -EINVAL;
 	}
 
+	spin_lock_bh(&nr_node_list_lock);
 	nr_node_lock(nr_node);
 	for (i = 0; i < nr_node->count; i++) {
 		if (nr_node->routes[i].neighbour == nr_neigh) {
@@ -352,7 +345,7 @@ static int nr_del_node(ax25_address *callsign, ax25_address *neighbour, struct n
 			nr_node->count--;
 
 			if (nr_node->count == 0) {
-				nr_remove_node(nr_node);
+				nr_remove_node_locked(nr_node);
 			} else {
 				switch (i) {
 				case 0:
@@ -367,12 +360,14 @@ static int nr_del_node(ax25_address *callsign, ax25_address *neighbour, struct n
 				nr_node_put(nr_node);
 			}
 			nr_node_unlock(nr_node);
+			spin_unlock_bh(&nr_node_list_lock);
 
 			return 0;
 		}
 	}
 	nr_neigh_put(nr_neigh);
 	nr_node_unlock(nr_node);
+	spin_unlock_bh(&nr_node_list_lock);
 	nr_node_put(nr_node);
 
 	return -EINVAL;




[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux