From: Greg Kroah-Hartman Date: Mon, 4 Mar 2024 11:45:56 +0000 (+0100) Subject: 5.15-stable patches X-Git-Tag: v4.19.309~36 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=76958f9dfb2091b1d0abd2337f22d34adcaf2d1d;p=thirdparty%2Fkernel%2Fstable-queue.git 5.15-stable patches added patches: af_unix-drop-oob_skb-ref-before-purging-queue-in-gc.patch --- diff --git a/queue-5.15/af_unix-drop-oob_skb-ref-before-purging-queue-in-gc.patch b/queue-5.15/af_unix-drop-oob_skb-ref-before-purging-queue-in-gc.patch new file mode 100644 index 00000000000..210f712c4b1 --- /dev/null +++ b/queue-5.15/af_unix-drop-oob_skb-ref-before-purging-queue-in-gc.patch @@ -0,0 +1,106 @@ +From aa82ac51d63328714645c827775d64dbfd9941f3 Mon Sep 17 00:00:00 2001 +From: Kuniyuki Iwashima +Date: Mon, 19 Feb 2024 09:46:57 -0800 +Subject: af_unix: Drop oob_skb ref before purging queue in GC. + +From: Kuniyuki Iwashima + +commit aa82ac51d63328714645c827775d64dbfd9941f3 upstream. + +syzbot reported another task hung in __unix_gc(). [0] + +The current while loop assumes that all of the left candidates +have oob_skb and calling kfree_skb(oob_skb) releases the remaining +candidates. + +However, I missed a case that oob_skb has self-referencing fd and +another fd and the latter sk is placed before the former in the +candidate list. Then, the while loop never proceeds, resulting +the task hung. + +__unix_gc() has the same loop just before purging the collected skb, +so we can call kfree_skb(oob_skb) there and let __skb_queue_purge() +release all inflight sockets. + +[0]: +Sending NMI from CPU 0 to CPUs 1: +NMI backtrace for cpu 1 +CPU: 1 PID: 2784 Comm: kworker/u4:8 Not tainted 6.8.0-rc4-syzkaller-01028-g71b605d32017 #0 +Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 +Workqueue: events_unbound __unix_gc +RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:200 +Code: 89 fb e8 23 00 00 00 48 8b 3d 84 f5 1a 0c 48 89 de 5b e9 43 26 57 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0d 90 52 70 7e 65 8b 15 91 52 70 +RSP: 0018:ffffc9000a17fa78 EFLAGS: 00000287 +RAX: ffffffff8a0a6108 RBX: ffff88802b6c2640 RCX: ffff88802c0b3b80 +RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000 +RBP: ffffc9000a17fbf0 R08: ffffffff89383f1d R09: 1ffff1100ee5ff84 +R10: dffffc0000000000 R11: ffffed100ee5ff85 R12: 1ffff110056d84ee +R13: ffffc9000a17fae0 R14: 0000000000000000 R15: ffffffff8f47b840 +FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 +CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 +CR2: 00007ffef5687ff8 CR3: 0000000029b34000 CR4: 00000000003506f0 +DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 +DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 +Call Trace: + + + + __unix_gc+0xe69/0xf40 net/unix/garbage.c:343 + process_one_work kernel/workqueue.c:2633 [inline] + process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706 + worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787 + kthread+0x2ef/0x390 kernel/kthread.c:388 + ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 + ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242 + + +Reported-and-tested-by: syzbot+ecab4d36f920c3574bf9@syzkaller.appspotmail.com +Closes: https://syzkaller.appspot.com/bug?extid=ecab4d36f920c3574bf9 +Fixes: 25236c91b5ab ("af_unix: Fix task hung while purging oob_skb in GC.") +Signed-off-by: Kuniyuki Iwashima +Signed-off-by: David S. Miller +Signed-off-by: Greg Kroah-Hartman +--- + net/unix/garbage.c | 22 +++++++++------------- + 1 file changed, 9 insertions(+), 13 deletions(-) + +--- a/net/unix/garbage.c ++++ b/net/unix/garbage.c +@@ -284,9 +284,17 @@ void unix_gc(void) + * which are creating the cycle(s). + */ + skb_queue_head_init(&hitlist); +- list_for_each_entry(u, &gc_candidates, link) ++ list_for_each_entry(u, &gc_candidates, link) { + scan_children(&u->sk, inc_inflight, &hitlist); + ++#if IS_ENABLED(CONFIG_AF_UNIX_OOB) ++ if (u->oob_skb) { ++ kfree_skb(u->oob_skb); ++ u->oob_skb = NULL; ++ } ++#endif ++ } ++ + /* not_cycle_list contains those sockets which do not make up a + * cycle. Restore these to the inflight list. + */ +@@ -314,18 +322,6 @@ void unix_gc(void) + /* Here we are. Hitlist is filled. Die. */ + __skb_queue_purge(&hitlist); + +-#if IS_ENABLED(CONFIG_AF_UNIX_OOB) +- while (!list_empty(&gc_candidates)) { +- u = list_entry(gc_candidates.next, struct unix_sock, link); +- if (u->oob_skb) { +- struct sk_buff *skb = u->oob_skb; +- +- u->oob_skb = NULL; +- kfree_skb(skb); +- } +- } +-#endif +- + spin_lock(&unix_gc_lock); + + /* There could be io_uring registered files, just push them back to diff --git a/queue-5.15/series b/queue-5.15/series index fdb52ce6142..d8cb3a303f8 100644 --- a/queue-5.15/series +++ b/queue-5.15/series @@ -71,3 +71,4 @@ mptcp-fix-possible-deadlock-in-subflow-diag.patch cachefiles-fix-memory-leak-in-cachefiles_add_cache.patch fs-hugetlb-fix-null-pointer-dereference-in-hugetlbs_fill_super.patch revert-drm-bridge-lt8912b-register-and-attach-our-dsi-device-at-probe.patch +af_unix-drop-oob_skb-ref-before-purging-queue-in-gc.patch