| Message ID | 20211004195522.2041705-1-eric.dumazet@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | a56d447f196fa9973c568f54c0d76d5391c3b0c0 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] net/sched: sch_taprio: properly cancel timer from taprio_destroy() | expand |
Eric Dumazet <eric.dumazet@gmail.com> writes: > From: Eric Dumazet <edumazet@google.com> > > There is a comment in qdisc_create() about us not calling ops->reset() > in some cases. > > err_out4: > /* > * Any broken qdiscs that would require a ops->reset() here? > * The qdisc was never in action so it shouldn't be necessary. > */ > > As taprio sets a timer before actually receiving a packet, we need > to cancel it from ops->destroy, just in case ops->reset has not > been called. > > syzbot reported: > > ODEBUG: free active (active state 0) object type: hrtimer hint: advance_sched+0x0/0x9a0 arch/x86/include/asm/atomic64_64.h:22 > WARNING: CPU: 0 PID: 8441 at lib/debugobjects.c:505 debug_print_object+0x16e/0x250 lib/debugobjects.c:505 > Modules linked in: > CPU: 0 PID: 8441 Comm: syz-executor813 Not tainted 5.14.0-rc6-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:505 > Code: ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 af 00 00 00 48 8b 14 dd e0 d3 e3 89 4c 89 ee 48 c7 c7 e0 c7 e3 89 e8 5b 86 11 05 <0f> 0b 83 05 85 03 92 09 01 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e c3 > RSP: 0018:ffffc9000130f330 EFLAGS: 00010282 > RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 > RDX: ffff88802baeb880 RSI: ffffffff815d87b5 RDI: fffff52000261e58 > RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 > R10: ffffffff815d25ee R11: 0000000000000000 R12: ffffffff898dd020 > R13: ffffffff89e3ce20 R14: ffffffff81653630 R15: dffffc0000000000 > FS: 0000000000f0d300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007ffb64b3e000 CR3: 0000000036557000 CR4: 00000000001506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > __debug_check_no_obj_freed lib/debugobjects.c:987 [inline] > debug_check_no_obj_freed+0x301/0x420 lib/debugobjects.c:1018 > slab_free_hook mm/slub.c:1603 [inline] > slab_free_freelist_hook+0x171/0x240 mm/slub.c:1653 > slab_free mm/slub.c:3213 [inline] > kfree+0xe4/0x540 mm/slub.c:4267 > qdisc_create+0xbcf/0x1320 net/sched/sch_api.c:1299 > tc_modify_qdisc+0x4c8/0x1a60 net/sched/sch_api.c:1663 > rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5571 > netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504 > netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] > netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340 > netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929 > sock_sendmsg_nosec net/socket.c:704 [inline] > sock_sendmsg+0xcf/0x120 net/socket.c:724 > ____sys_sendmsg+0x6e8/0x810 net/socket.c:2403 > ___sys_sendmsg+0xf3/0x170 net/socket.c:2457 > __sys_sendmsg+0xe5/0x1b0 net/socket.c:2486 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > > Fixes: 44d4775ca518 ("net/sched: sch_taprio: reset child qdiscs before freeing them") > Signed-off-by: Eric Dumazet <edumazet@google.com> > Cc: Davide Caratti <dcaratti@redhat.com> > Reported-by: syzbot <syzkaller@googlegroups.com> > --- Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
hello Eric, thanks for the patch! On Mon, Oct 04, 2021 at 12:55:22PM -0700, Eric Dumazet wrote: > From: Eric Dumazet <edumazet@google.com> > > There is a comment in qdisc_create() about us not calling ops->reset() > in some cases. > > err_out4: > /* > * Any broken qdiscs that would require a ops->reset() here? > * The qdisc was never in action so it shouldn't be necessary. > */ right, I didn't spot this error path. > Fixes: 44d4775ca518 ("net/sched: sch_taprio: reset child qdiscs before freeing them") > Signed-off-by: Eric Dumazet <edumazet@google.com> > Cc: Davide Caratti <dcaratti@redhat.com> > Reported-by: syzbot <syzkaller@googlegroups.com> Acked-by: Davide Caratti <dcaratti@redhat.com> > --- > net/sched/sch_taprio.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c > index 1ab2fc933a214d04dfff763d2c5de65f4a67374a..b9fd18d986464f317a9fb7ce709a9728ffb75751 100644 > --- a/net/sched/sch_taprio.c > +++ b/net/sched/sch_taprio.c > @@ -1641,6 +1641,10 @@ static void taprio_destroy(struct Qdisc *sch) > list_del(&q->taprio_list); > spin_unlock(&taprio_list_lock); > > + /* Note that taprio_reset() might not be called if an error > + * happens in qdisc_create(), after taprio_init() has been called. > + */ > + hrtimer_cancel(&q->advance_timer); > > taprio_disable_offload(dev, q, NULL); > > -- > 2.33.0.800.g4c38ced690-goog >
Hello: This patch was applied to netdev/net.git (refs/heads/master): On Mon, 4 Oct 2021 12:55:22 -0700 you wrote: > From: Eric Dumazet <edumazet@google.com> > > There is a comment in qdisc_create() about us not calling ops->reset() > in some cases. > > err_out4: > /* > * Any broken qdiscs that would require a ops->reset() here? > * The qdisc was never in action so it shouldn't be necessary. > */ > > [...] Here is the summary with links: - [net] net/sched: sch_taprio: properly cancel timer from taprio_destroy() https://git.kernel.org/netdev/net/c/a56d447f196f You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 1ab2fc933a214d04dfff763d2c5de65f4a67374a..b9fd18d986464f317a9fb7ce709a9728ffb75751 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -1641,6 +1641,10 @@ static void taprio_destroy(struct Qdisc *sch) list_del(&q->taprio_list); spin_unlock(&taprio_list_lock); + /* Note that taprio_reset() might not be called if an error + * happens in qdisc_create(), after taprio_init() has been called. + */ + hrtimer_cancel(&q->advance_timer); taprio_disable_offload(dev, q, NULL);