| Message ID | 20240622045701.8152-2-yskelg@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v3] tracing/net_sched: NULL pointer dereference in perf_trace_qdisc_reset() | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
On Sat, Jun 22, 2024 at 1:58 PM <yskelg@gmail.com> wrote: > > From: Yunseong Kim <yskelg@gmail.com> > Hi Yunseong, Thanks a lot for this work! > In the TRACE_EVENT(qdisc_reset) NULL dereference occurred from > > qdisc->dev_queue->dev <NULL> ->name > > This situation simulated from bunch of veths and Bluetooth dis/reconnection. > > During qdisc initialization, qdisc was being set to noop_queue. > In veth_init_queue, the initial tx_num was reduced back to one, > causing the qdisc reset to be called with noop, which led to the kernel panic. > > I've attached the GitHub gist link that C converted syz-execprogram > source code and 3 log of reproduced vmcore-dmesg. > > https://gist.github.com/yskelg/cc64562873ce249cdd0d5a358b77d740 > > Yeoreum and I use two fuzzing tool simultaneously. > > One process with syz-executor : https://github.com/google/syzkaller > > $ ./syz-execprog -executor=./syz-executor -repeat=1 -sandbox=setuid \ > -enable=none -collide=false log1 > > The other process with perf fuzzer: > https://github.com/deater/perf_event_tests/tree/master/fuzzer > > $ perf_event_tests/fuzzer/perf_fuzzer > > I think this will happen on the kernel version. > > Linux kernel version +v6.7.10, +v6.8, +v6.9 and it could happen in v6.10. > > This occurred from 51270d573a8d. I think this patch is absolutely > necessary. Previously, It was showing not intended string value of name. > > I've reproduced 3 time from my fedora 40 Debug Kernel with any other module > or patched. > > version: 6.10.0-0.rc2.20240608gitdc772f8237f9.29.fc41.aarch64+debug > > [ 5287.164555] veth0_vlan: left promiscuous mode > [ 5287.164929] veth1_macvtap: left promiscuous mode > [ 5287.164950] veth0_macvtap: left promiscuous mode > [ 5287.164983] veth1_vlan: left promiscuous mode > [ 5287.165008] veth0_vlan: left promiscuous mode > [ 5287.165450] veth1_macvtap: left promiscuous mode > [ 5287.165472] veth0_macvtap: left promiscuous mode > [ 5287.165502] veth1_vlan: left promiscuous mode > … > [ 5297.598240] bridge0: port 2(bridge_slave_1) entered blocking state > [ 5297.598262] bridge0: port 2(bridge_slave_1) entered forwarding state > [ 5297.598296] bridge0: port 1(bridge_slave_0) entered blocking state > [ 5297.598313] bridge0: port 1(bridge_slave_0) entered forwarding state > [ 5297.616090] 8021q: adding VLAN 0 to HW filter on device bond0 > [ 5297.620405] bridge0: port 1(bridge_slave_0) entered disabled state > [ 5297.620730] bridge0: port 2(bridge_slave_1) entered disabled state > [ 5297.627247] 8021q: adding VLAN 0 to HW filter on device team0 > [ 5297.629636] bridge0: port 1(bridge_slave_0) entered blocking state > … > [ 5298.002798] bridge_slave_0: left promiscuous mode > [ 5298.002869] bridge0: port 1(bridge_slave_0) entered disabled state > [ 5298.309444] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface > [ 5298.315206] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface > [ 5298.320207] bond0 (unregistering): Released all slaves > [ 5298.354296] hsr_slave_0: left promiscuous mode > [ 5298.360750] hsr_slave_1: left promiscuous mode > [ 5298.374889] veth1_macvtap: left promiscuous mode > [ 5298.374931] veth0_macvtap: left promiscuous mode > [ 5298.374988] veth1_vlan: left promiscuous mode > [ 5298.375024] veth0_vlan: left promiscuous mode > [ 5299.109741] team0 (unregistering): Port device team_slave_1 removed > [ 5299.185870] team0 (unregistering): Port device team_slave_0 removed > … > [ 5300.155443] Bluetooth: hci3: unexpected cc 0x0c03 length: 249 > 1 > [ 5300.155724] Bluetooth: hci3: unexpected cc 0x1003 length: 249 > 9 > [ 5300.155988] Bluetooth: hci3: unexpected cc 0x1001 length: 249 > 9 > …. > [ 5301.075531] team0: Port device team_slave_1 added > [ 5301.085515] bridge0: port 1(bridge_slave_0) entered blocking state > [ 5301.085531] bridge0: port 1(bridge_slave_0) entered disabled state > [ 5301.085588] bridge_slave_0: entered allmulticast mode > [ 5301.085800] bridge_slave_0: entered promiscuous mode > [ 5301.095617] bridge0: port 1(bridge_slave_0) entered blocking state > [ 5301.095633] bridge0: port 1(bridge_slave_0) entered disabled state > … > [ 5301.149734] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link > [ 5301.173234] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link > [ 5301.180517] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link > [ 5301.193481] hsr_slave_0: entered promiscuous mode > [ 5301.204425] hsr_slave_1: entered promiscuous mode > [ 5301.210172] debugfs: Directory 'hsr0' with parent 'hsr' already present! > [ 5301.210185] Cannot create hsr debugfs directory > [ 5301.224061] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link > [ 5301.246901] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link > [ 5301.255934] team0: Port device team_slave_0 added > [ 5301.256480] team0: Port device team_slave_1 added > [ 5301.256948] team0: Port device team_slave_0 added > … > [ 5301.435928] hsr_slave_0: entered promiscuous mode > [ 5301.446029] hsr_slave_1: entered promiscuous mode > [ 5301.455872] debugfs: Directory 'hsr0' with parent 'hsr' already present! > [ 5301.455884] Cannot create hsr debugfs directory > [ 5301.502664] hsr_slave_0: entered promiscuous mode > [ 5301.513675] hsr_slave_1: entered promiscuous mode > [ 5301.526155] debugfs: Directory 'hsr0' with parent 'hsr' already present! > [ 5301.526164] Cannot create hsr debugfs directory > [ 5301.563662] hsr_slave_0: entered promiscuous mode > [ 5301.576129] hsr_slave_1: entered promiscuous mode > [ 5301.580259] debugfs: Directory 'hsr0' with parent 'hsr' already present! > [ 5301.580270] Cannot create hsr debugfs directory > [ 5301.590269] 8021q: adding VLAN 0 to HW filter on device bond0 > > [ 5301.595872] KASAN: null-ptr-deref in range [0x0000000000000130-0x0000000000000137] > [ 5301.595877] Mem abort info: > [ 5301.595881] ESR = 0x0000000096000006 > [ 5301.595885] EC = 0x25: DABT (current EL), IL = 32 bits > [ 5301.595889] SET = 0, FnV = 0 > [ 5301.595893] EA = 0, S1PTW = 0 > [ 5301.595896] FSC = 0x06: level 2 translation fault > [ 5301.595900] Data abort info: > [ 5301.595903] ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 > [ 5301.595907] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 > [ 5301.595911] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 > [ 5301.595915] [dfff800000000026] address between user and kernel address ranges > [ 5301.595971] Internal error: Oops: 0000000096000006 [#1] SMP > … > [ 5301.596076] CPU: 2 PID: 102769 Comm: > syz-executor.3 Kdump: loaded Tainted: > G W ------- --- 6.10.0-0.rc2.20240608gitdc772f8237f9.29.fc41.aarch64+debug #1 > [ 5301.596080] Hardware name: VMware, Inc. VMware20,1/VBSA, > BIOS VMW201.00V.21805430.BA64.2305221830 05/22/2023 > [ 5301.596082] pstate: 01400005 (nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) > [ 5301.596085] pc : strnlen+0x40/0x88 > [ 5301.596114] lr : trace_event_get_offsets_qdisc_reset+0x6c/0x2b0 > [ 5301.596124] sp : ffff8000beef6b40 > [ 5301.596126] x29: ffff8000beef6b40 x28: dfff800000000000 x27: 0000000000000001 > [ 5301.596131] x26: 6de1800082c62bd0 x25: 1ffff000110aa9e0 x24: ffff800088554f00 > [ 5301.596136] x23: ffff800088554ec0 x22: 0000000000000130 x21: 0000000000000140 > [ 5301.596140] x20: dfff800000000000 x19: ffff8000beef6c60 x18: ffff7000115106d8 > [ 5301.596143] x17: ffff800121bad000 x16: ffff800080020000 x15: 0000000000000006 > [ 5301.596147] x14: 0000000000000002 x13: ffff0001f3ed8d14 x12: ffff700017ddeda5 > [ 5301.596151] x11: 1ffff00017ddeda4 x10: ffff700017ddeda4 x9 : ffff800082cc5eec > [ 5301.596155] x8 : 0000000000000004 x7 : 00000000f1f1f1f1 x6 : 00000000f2f2f200 > [ 5301.596158] x5 : 00000000f3f3f3f3 x4 : ffff700017dded80 x3 : 00000000f204f1f1 > [ 5301.596162] x2 : 0000000000000026 x1 : 0000000000000000 x0 : 0000000000000130 > [ 5301.596166] Call trace: > [ 5301.596175] strnlen+0x40/0x88 > [ 5301.596179] trace_event_get_offsets_qdisc_reset+0x6c/0x2b0 > [ 5301.596182] perf_trace_qdisc_reset+0xb0/0x538 > [ 5301.596184] __traceiter_qdisc_reset+0x68/0xc0 > [ 5301.596188] qdisc_reset+0x43c/0x5e8 > [ 5301.596190] netif_set_real_num_tx_queues+0x288/0x770 > [ 5301.596194] veth_init_queues+0xfc/0x130 [veth] > [ 5301.596198] veth_newlink+0x45c/0x850 [veth] > [ 5301.596202] rtnl_newlink_create+0x2c8/0x798 > [ 5301.596205] __rtnl_newlink+0x92c/0xb60 > [ 5301.596208] rtnl_newlink+0xd8/0x130 > [ 5301.596211] rtnetlink_rcv_msg+0x2e0/0x890 > [ 5301.596214] netlink_rcv_skb+0x1c4/0x380 > [ 5301.596225] rtnetlink_rcv+0x20/0x38 > [ 5301.596227] netlink_unicast+0x3c8/0x640 > [ 5301.596231] netlink_sendmsg+0x658/0xa60 > [ 5301.596234] __sock_sendmsg+0xd0/0x180 > [ 5301.596243] __sys_sendto+0x1c0/0x280 > [ 5301.596246] __arm64_sys_sendto+0xc8/0x150 > [ 5301.596249] invoke_syscall+0xdc/0x268 > [ 5301.596256] el0_svc_common.constprop.0+0x16c/0x240 > [ 5301.596259] do_el0_svc+0x48/0x68 > [ 5301.596261] el0_svc+0x50/0x188 > [ 5301.596265] el0t_64_sync_handler+0x120/0x130 > [ 5301.596268] el0t_64_sync+0x194/0x198 > [ 5301.596272] Code: eb15001f 54000120 d343fc02 12000801 (38f46842) > [ 5301.596285] SMP: stopping secondary CPUs > [ 5301.597053] Starting crashdump kernel... > [ 5301.597057] Bye! > > Yeoreum and I don't know if the patch we wrote will fix the underlying cause, > but we think that priority is to prevent kernel panic happening. > So, we're sending this patch. > > Link: https://lore.kernel.org/lkml/20240229143432.273b4871@gandalf.local.home/t/ > Fixes: 51270d573a8d ("tracing/net_sched: Fix tracepoints that save qdisc_dev() as a string") > Cc: netdev@vger.kernel.org > Cc: stable@vger.kernel.org # +v6.7.10, +v6.8 > Signed-off-by: Yunseong Kim <yskelg@gmail.com> > Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com> > --- > include/trace/events/qdisc.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/trace/events/qdisc.h b/include/trace/events/qdisc.h > index f1b5e816e7e5..170b51fbe47a 100644 > --- a/include/trace/events/qdisc.h > +++ b/include/trace/events/qdisc.h > @@ -81,7 +81,7 @@ TRACE_EVENT(qdisc_reset, > TP_ARGS(q), > > TP_STRUCT__entry( > - __string( dev, qdisc_dev(q)->name ) > + __string(dev, qdisc_dev(q) ? qdisc_dev(q)->name : "noop_queue") > __string( kind, q->ops->id ) > __field( u32, parent ) > __field( u32, handle ) > -- > 2.45.2 > I found a simple reproducer, please use the below command to test this patch. echo 1 > /sys/kernel/debug/tracing/events/enable ip link add veth0 type veth peer name veth1 In my machine, the splat looks like: BUG: kernel NULL pointer dereference, address: 0000000000000130 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 1207 Comm: ip Not tainted 6.10.0-rc4+ #25 362ec22a686962a9936425abea9a73f03b445c0c Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021 RIP: 0010:strlen+0x0/0x20 Code: f7 75 ec 31 c0 c3 cc cc cc cc 48 89 f8 c3 cc cc cc cc 0f 1f 84 00 00 00 00 00 90 90 90 90 9c RSP: 0018:ffffbed8435c7630 EFLAGS: 00010206 RAX: ffffffff92d629c0 RBX: ffffa14100185c60 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffffffff92d62840 RDI: 0000000000000130 RBP: ffffffff92dc4600 R08: 0000000000000fd0 R09: 0000000000000010 R10: ffffffff92c66c98 R11: 0000000000000001 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000130 R15: ffffffff92d62840 FS: 00007f6a94e50b80(0000) GS:ffffa1485f680000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000130 CR3: 0000000103414000 CR4: 00000000007506f0 PKRU: 55555554 Call Trace: <TASK> ? __die+0x20/0x70 ? page_fault_oops+0x15a/0x460 ? trace_event_raw_event_x86_exceptions+0x5f/0xa0 ? exc_page_fault+0x6e/0x180 ? asm_exc_page_fault+0x22/0x30 ? __pfx_strlen+0x10/0x10 trace_event_raw_event_qdisc_reset+0x4d/0x180 ? synchronize_rcu_expedited+0x215/0x240 ? __pfx_autoremove_wake_function+0x10/0x10 qdisc_reset+0x130/0x150 netif_set_real_num_tx_queues+0xe3/0x1e0 veth_init_queues+0x44/0x70 [veth 24a9dd1cd1b1b279e1b467ad46d47a753799b428] veth_newlink+0x22b/0x440 [veth 24a9dd1cd1b1b279e1b467ad46d47a753799b428] __rtnl_newlink+0x718/0x990 rtnl_newlink+0x44/0x70 rtnetlink_rcv_msg+0x159/0x410 ? kmalloc_reserve+0x90/0xf0 ? trace_event_raw_event_kmem_cache_alloc+0x87/0xe0 ? __pfx_rtnetlink_rcv_msg+0x10/0x10 netlink_rcv_skb+0x54/0x100 netlink_unicast+0x243/0x370 netlink_sendmsg+0x1bb/0x3e0 ____sys_sendmsg+0x2bb/0x320 ? copy_msghdr_from_user+0x6d/0xa0 ___sys_sendmsg+0x88/0xd0 Thanks a lot! Taehee Yoo
Hi Taehee, On 6/22/24 2:50 오후, Taehee Yoo wrote: > On Sat, Jun 22, 2024 at 1:58 PM <yskelg@gmail.com> wrote: >> >> From: Yunseong Kim <yskelg@gmail.com> >> > > Hi Yunseong, > Thanks a lot for this work! Thank you Taehee for reviewing our patch. It's greatly appreciated. >> During qdisc initialization, qdisc was being set to noop_queue. >> In veth_init_queue, the initial tx_num was reduced back to one, >> causing the qdisc reset to be called with noop, which led to the kernel panic. >> >> I've attached the GitHub gist link that C converted syz-execprogram >> source code and 3 log of reproduced vmcore-dmesg. >> >> https://gist.github.com/yskelg/cc64562873ce249cdd0d5a358b77d740 >> >> Yeoreum and I use two fuzzing tool simultaneously. >> >> One process with syz-executor : https://github.com/google/syzkaller >> >> $ ./syz-execprog -executor=./syz-executor -repeat=1 -sandbox=setuid \ >> -enable=none -collide=false log1 >> >> The other process with perf fuzzer: >> https://github.com/deater/perf_event_tests/tree/master/fuzzer >> >> $ perf_event_tests/fuzzer/perf_fuzzer >> >> I think this will happen on the kernel version. >> >> Linux kernel version +v6.7.10, +v6.8, +v6.9 and it could happen in v6.10. >> >> This occurred from 51270d573a8d. I think this patch is absolutely >> necessary. Previously, It was showing not intended string value of name. > I found a simple reproducer, please use the below command to test this patch. > > echo 1 > /sys/kernel/debug/tracing/events/enable > ip link add veth0 type veth peer name veth1 The perf event is activated by perf_fuzzer, and it's indeed a similar environment with veth. > In my machine, the splat looks like: > > BUG: kernel NULL pointer dereference, address: 0000000000000130 > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 0 P4D 0 > Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI > CPU: 1 PID: 1207 Comm: ip Not tainted 6.10.0-rc4+ #25 > 362ec22a686962a9936425abea9a73f03b445c0c > Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021 > RIP: 0010:strlen+0x0/0x20 > Code: f7 75 ec 31 c0 c3 cc cc cc cc 48 89 f8 c3 cc cc cc cc 0f 1f 84 > 00 00 00 00 00 90 90 90 90 9c > RSP: 0018:ffffbed8435c7630 EFLAGS: 00010206 > RAX: ffffffff92d629c0 RBX: ffffa14100185c60 RCX: 0000000000000000 > RDX: 0000000000000001 RSI: ffffffff92d62840 RDI: 0000000000000130 > RBP: ffffffff92dc4600 R08: 0000000000000fd0 R09: 0000000000000010 > R10: ffffffff92c66c98 R11: 0000000000000001 R12: 0000000000000001 > R13: 0000000000000000 R14: 0000000000000130 R15: ffffffff92d62840 > FS: 00007f6a94e50b80(0000) GS:ffffa1485f680000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000130 CR3: 0000000103414000 CR4: 00000000007506f0 > PKRU: 55555554 > Call Trace: > <TASK> > ? __die+0x20/0x70 > ? page_fault_oops+0x15a/0x460 > ? trace_event_raw_event_x86_exceptions+0x5f/0xa0 > ? exc_page_fault+0x6e/0x180 > ? asm_exc_page_fault+0x22/0x30 > ? __pfx_strlen+0x10/0x10 > trace_event_raw_event_qdisc_reset+0x4d/0x180 > ? synchronize_rcu_expedited+0x215/0x240 > ? __pfx_autoremove_wake_function+0x10/0x10 > qdisc_reset+0x130/0x150 > netif_set_real_num_tx_queues+0xe3/0x1e0 > veth_init_queues+0x44/0x70 [veth 24a9dd1cd1b1b279e1b467ad46d47a753799b428] > veth_newlink+0x22b/0x440 [veth 24a9dd1cd1b1b279e1b467ad46d47a753799b428] > __rtnl_newlink+0x718/0x990 > rtnl_newlink+0x44/0x70 > rtnetlink_rcv_msg+0x159/0x410 > ? kmalloc_reserve+0x90/0xf0 > ? trace_event_raw_event_kmem_cache_alloc+0x87/0xe0 > ? __pfx_rtnetlink_rcv_msg+0x10/0x10 > netlink_rcv_skb+0x54/0x100 > netlink_unicast+0x243/0x370 > netlink_sendmsg+0x1bb/0x3e0 > ____sys_sendmsg+0x2bb/0x320 > ? copy_msghdr_from_user+0x6d/0xa0 > ___sys_sendmsg+0x88/0xd0 > > Thanks a lot! > Taehee Yoo I think this bug might cause inconvenience for developers working on net devices driver in a virtual machine when they use tracing. I'm appreciate your effort in reproducing it. Warm Regards, Yunseong Kim
Hi, On 6/22/24 3:12 오후, Yunseong Kim wrote: > Hi Taehee, > > On 6/22/24 2:50 오후, Taehee Yoo wrote: >> On Sat, Jun 22, 2024 at 1:58 PM <yskelg@gmail.com> wrote: >>> >>> From: Yunseong Kim <yskelg@gmail.com> >>> >> >> Hi Yunseong, >> Thanks a lot for this work! > > Thank you Taehee for reviewing our patch. It's greatly appreciated. > >>> During qdisc initialization, qdisc was being set to noop_queue. >>> In veth_init_queue, the initial tx_num was reduced back to one, >>> causing the qdisc reset to be called with noop, which led to the kernel panic. >>> >>> I've attached the GitHub gist link that C converted syz-execprogram >>> source code and 3 log of reproduced vmcore-dmesg. >>> >>> https://gist.github.com/yskelg/cc64562873ce249cdd0d5a358b77d740 >>> >>> Yeoreum and I use two fuzzing tool simultaneously. >>> >>> One process with syz-executor : https://github.com/google/syzkaller >>> >>> $ ./syz-execprog -executor=./syz-executor -repeat=1 -sandbox=setuid \ >>> -enable=none -collide=false log1 >>> >>> The other process with perf fuzzer: >>> https://github.com/deater/perf_event_tests/tree/master/fuzzer >>> >>> $ perf_event_tests/fuzzer/perf_fuzzer >>> >>> I think this will happen on the kernel version. >>> >>> Linux kernel version +v6.7.10, +v6.8, +v6.9 and it could happen in v6.10. >>> >>> This occurred from 51270d573a8d. I think this patch is absolutely >>> necessary. Previously, It was showing not intended string value of name. > > >> I found a simple reproducer, please use the below command to test this patch. >> >> echo 1 > /sys/kernel/debug/tracing/events/enable >> ip link add veth0 type veth peer name veth1 After applying our patch, I didn't find any message or kernel panic errors. # echo 1 > /sys/kernel/debug/tracing/events/qdisc/qdisc_reset/enable # ip link add veth0 type veth peer name veth1 Error: Unknown device type. However, without our patch applied, I tested Tahee's command line on the upstream 6.10.0-rc3 kernel using the qdisc_reset event and the ip command. $ echo 1 > /sys/kernel/debug/tracing/events/qdisc/qdisc_reset/enable $ ip link add veth0 type veth peer name veth1 This make always kernel panic. Linux version: 6.10.0-rc3 [ 0.000000] Linux version 6.10.0-rc3-00164-g44ef20baed8e-dirty (paran@fedora) (gcc (GCC) 14.1.1 20240522 (Red Hat 14.1.1-4), GNU ld version 2.41-34.fc40) #20 SMP PREEMPT Sat Jun 15 16:51:25 KST 2024 Kernel panic message: [ 615.236484] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP [ 615.237250] Dumping ftrace buffer: [ 615.237679] (ftrace buffer empty) [ 615.238097] Modules linked in: veth crct10dif_ce virtio_gpu virtio_dma_buf drm_shmem_helper drm_kms_helper zynqmp_fpga xilinx_can xilinx_spi xilinx_selectmap xilinx_core xilinx_pr_decoupler versal_fpga uvcvideo uvc videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videodev videobuf2_common mc usbnet deflate zstd ubifs ubi rcar_canfd rcar_can omap_mailbox ntb_msi_test ntb_hw_epf lattice_sysconfig_spi lattice_sysconfig ice40_spi gpio_xilinx dwmac_altr_socfpga mdio_regmap stmmac_platform stmmac pcs_xpcs dfl_fme_region dfl_fme_mgr dfl_fme_br dfl_afu dfl fpga_region fpga_bridge can can_dev br_netfilter bridge stp llc atl1c ath11k_pci mhi ath11k_ahb ath11k qmi_helpers ath10k_sdio ath10k_pci ath10k_core ath mac80211 libarc4 cfg80211 drm fuse backlight ipv6 Jun 22 02:36:5[3 6k152.62-4sm98k4-0k]v kCePUr:n e1l :P IUDn:a b4le6 8t oC ohmma: nidpl eN oketr nteali nptaedg i6n.g1 0re.0q-urecs3t- 0at0 1v6i4r-tgu4a4le fa2d0dbraeeds0se-dir tyd f#f2f08 615.252376] Hardware name: linux,dummy-virt (DT) [ 615.253220] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 615.254433] pc : strnlen+0x6c/0xe0 [ 615.255096] lr : trace_event_get_offsets_qdisc_reset+0x94/0x3d0 [ 615.256088] sp : ffff800080b269a0 [ 615.256615] x29: ffff800080b269a0 x28: ffffc070f3f98500 x27: 0000000000000001 [ 615.257831] x26: 0000000000000010 x25: ffffc070f3f98540 x24: ffffc070f619cf60 [ 615.259020] x23: 0000000000000128 x22: 0000000000000138 x21: dfff800000000000 [ 615.260241] x20: ffffc070f631ad00 x19: 0000000000000128 x18: ffffc070f448b800 [ 615.261454] x17: 0000000000000000 x16: 0000000000000001 x15: ffffc070f4ba2a90 [ 615.262635] x14: ffff700010164d73 x13: 1ffff80e1e8d5eb3 x12: 1ffff00010164d72 [ 615.263877] x11: ffff700010164d72 x10: dfff800000000000 x9 : ffffc070e85d6184 [ 615.265047] x8 : ffffc070e4402070 x7 : 000000000000f1f1 x6 : 000000001504a6d3 [ 615.266336] x5 : ffff28ca21122140 x4 : ffffc070f5043ea8 x3 : 0000000000000000 [ 615.267528] x2 : 0000000000000025 x1 : 0000000000000000 x0 : 0000000000000000 [ 615.268747] Call trace: [ 615.269180] strnlen+0x6c/0xe0 [ 615.269767] trace_event_get_offsets_qdisc_reset+0x94/0x3d0 [ 615.270716] trace_event_raw_event_qdisc_reset+0xe8/0x4e8 [ 615.271667] __traceiter_qdisc_reset+0xa0/0x140 [ 615.272499] qdisc_reset+0x554/0x848 [ 615.273134] netif_set_real_num_tx_queues+0x360/0x9a8 [ 615.274050] veth_init_queues+0x110/0x220 [veth] [ 615.275110] veth_newlink+0x538/0xa50 [veth] [ 615.276172] __rtnl_newlink+0x11e4/0x1bc8 [ 615.276944] rtnl_newlink+0xac/0x120 [ 615.277657] rtnetlink_rcv_msg+0x4e4/0x1370 [ 615.278409] netlink_rcv_skb+0x25c/0x4f0 [ 615.279122] rtnetlink_rcv+0x48/0x70 [ 615.279769] netlink_unicast+0x5a8/0x7b8 [ 615.280462] netlink_sendmsg+0xa70/0x1190 > The perf event is activated by perf_fuzzer, and it's indeed a similar > environment with veth. > >> In my machine, the splat looks like: >> >> BUG: kernel NULL pointer dereference, address: 0000000000000130 >> #PF: supervisor read access in kernel mode >> Thanks a lot! >> Taehee Yoo > > I think this bug might cause inconvenience for developers working on net > devices driver in a virtual machine when they use tracing. > > I'm appreciate your effort in reproducing it. > > Warm Regards, > Yunseong Kim I believe our patch can prevent panics in all stable kernels released after +v6.7.10. Warm Regards, Yunseong Kim
On 22/06/2024 01:57, yskelg@gmail.com wrote: > From: Yunseong Kim <yskelg@gmail.com> > > In the TRACE_EVENT(qdisc_reset) NULL dereference occurred from > > qdisc->dev_queue->dev <NULL> ->name > > This situation simulated from bunch of veths and Bluetooth dis/reconnection. > > During qdisc initialization, qdisc was being set to noop_queue. > In veth_init_queue, the initial tx_num was reduced back to one, > causing the qdisc reset to be called with noop, which led to the kernel panic. > > I've attached the GitHub gist link that C converted syz-execprogram > source code and 3 log of reproduced vmcore-dmesg. > > https://gist.github.com/yskelg/cc64562873ce249cdd0d5a358b77d740 > > Yeoreum and I use two fuzzing tool simultaneously. > > One process with syz-executor : https://github.com/google/syzkaller > > $ ./syz-execprog -executor=./syz-executor -repeat=1 -sandbox=setuid \ > -enable=none -collide=false log1 > > The other process with perf fuzzer: > https://github.com/deater/perf_event_tests/tree/master/fuzzer > > $ perf_event_tests/fuzzer/perf_fuzzer > > I think this will happen on the kernel version. > > Linux kernel version +v6.7.10, +v6.8, +v6.9 and it could happen in v6.10. > > This occurred from 51270d573a8d. I think this patch is absolutely > necessary. Previously, It was showing not intended string value of name. > > I've reproduced 3 time from my fedora 40 Debug Kernel with any other module > or patched. > > version: 6.10.0-0.rc2.20240608gitdc772f8237f9.29.fc41.aarch64+debug > > [ 5287.164555] veth0_vlan: left promiscuous mode > [ 5287.164929] veth1_macvtap: left promiscuous mode > [ 5287.164950] veth0_macvtap: left promiscuous mode > [ 5287.164983] veth1_vlan: left promiscuous mode > [ 5287.165008] veth0_vlan: left promiscuous mode > [ 5287.165450] veth1_macvtap: left promiscuous mode > [ 5287.165472] veth0_macvtap: left promiscuous mode > [ 5287.165502] veth1_vlan: left promiscuous mode > … > [ 5297.598240] bridge0: port 2(bridge_slave_1) entered blocking state > [ 5297.598262] bridge0: port 2(bridge_slave_1) entered forwarding state > [ 5297.598296] bridge0: port 1(bridge_slave_0) entered blocking state > [ 5297.598313] bridge0: port 1(bridge_slave_0) entered forwarding state > [ 5297.616090] 8021q: adding VLAN 0 to HW filter on device bond0 > [ 5297.620405] bridge0: port 1(bridge_slave_0) entered disabled state > [ 5297.620730] bridge0: port 2(bridge_slave_1) entered disabled state > [ 5297.627247] 8021q: adding VLAN 0 to HW filter on device team0 > [ 5297.629636] bridge0: port 1(bridge_slave_0) entered blocking state > … > [ 5298.002798] bridge_slave_0: left promiscuous mode > [ 5298.002869] bridge0: port 1(bridge_slave_0) entered disabled state > [ 5298.309444] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface > [ 5298.315206] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface > [ 5298.320207] bond0 (unregistering): Released all slaves > [ 5298.354296] hsr_slave_0: left promiscuous mode > [ 5298.360750] hsr_slave_1: left promiscuous mode > [ 5298.374889] veth1_macvtap: left promiscuous mode > [ 5298.374931] veth0_macvtap: left promiscuous mode > [ 5298.374988] veth1_vlan: left promiscuous mode > [ 5298.375024] veth0_vlan: left promiscuous mode > [ 5299.109741] team0 (unregistering): Port device team_slave_1 removed > [ 5299.185870] team0 (unregistering): Port device team_slave_0 removed > … > [ 5300.155443] Bluetooth: hci3: unexpected cc 0x0c03 length: 249 > 1 > [ 5300.155724] Bluetooth: hci3: unexpected cc 0x1003 length: 249 > 9 > [ 5300.155988] Bluetooth: hci3: unexpected cc 0x1001 length: 249 > 9 > …. > [ 5301.075531] team0: Port device team_slave_1 added > [ 5301.085515] bridge0: port 1(bridge_slave_0) entered blocking state > [ 5301.085531] bridge0: port 1(bridge_slave_0) entered disabled state > [ 5301.085588] bridge_slave_0: entered allmulticast mode > [ 5301.085800] bridge_slave_0: entered promiscuous mode > [ 5301.095617] bridge0: port 1(bridge_slave_0) entered blocking state > [ 5301.095633] bridge0: port 1(bridge_slave_0) entered disabled state > … > [ 5301.149734] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link > [ 5301.173234] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link > [ 5301.180517] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link > [ 5301.193481] hsr_slave_0: entered promiscuous mode > [ 5301.204425] hsr_slave_1: entered promiscuous mode > [ 5301.210172] debugfs: Directory 'hsr0' with parent 'hsr' already present! > [ 5301.210185] Cannot create hsr debugfs directory > [ 5301.224061] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link > [ 5301.246901] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link > [ 5301.255934] team0: Port device team_slave_0 added > [ 5301.256480] team0: Port device team_slave_1 added > [ 5301.256948] team0: Port device team_slave_0 added > … > [ 5301.435928] hsr_slave_0: entered promiscuous mode > [ 5301.446029] hsr_slave_1: entered promiscuous mode > [ 5301.455872] debugfs: Directory 'hsr0' with parent 'hsr' already present! > [ 5301.455884] Cannot create hsr debugfs directory > [ 5301.502664] hsr_slave_0: entered promiscuous mode > [ 5301.513675] hsr_slave_1: entered promiscuous mode > [ 5301.526155] debugfs: Directory 'hsr0' with parent 'hsr' already present! > [ 5301.526164] Cannot create hsr debugfs directory > [ 5301.563662] hsr_slave_0: entered promiscuous mode > [ 5301.576129] hsr_slave_1: entered promiscuous mode > [ 5301.580259] debugfs: Directory 'hsr0' with parent 'hsr' already present! > [ 5301.580270] Cannot create hsr debugfs directory > [ 5301.590269] 8021q: adding VLAN 0 to HW filter on device bond0 > > [ 5301.595872] KASAN: null-ptr-deref in range [0x0000000000000130-0x0000000000000137] > [ 5301.595877] Mem abort info: > [ 5301.595881] ESR = 0x0000000096000006 > [ 5301.595885] EC = 0x25: DABT (current EL), IL = 32 bits > [ 5301.595889] SET = 0, FnV = 0 > [ 5301.595893] EA = 0, S1PTW = 0 > [ 5301.595896] FSC = 0x06: level 2 translation fault > [ 5301.595900] Data abort info: > [ 5301.595903] ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 > [ 5301.595907] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 > [ 5301.595911] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 > [ 5301.595915] [dfff800000000026] address between user and kernel address ranges > [ 5301.595971] Internal error: Oops: 0000000096000006 [#1] SMP > … > [ 5301.596076] CPU: 2 PID: 102769 Comm: > syz-executor.3 Kdump: loaded Tainted: > G W ------- --- 6.10.0-0.rc2.20240608gitdc772f8237f9.29.fc41.aarch64+debug #1 > [ 5301.596080] Hardware name: VMware, Inc. VMware20,1/VBSA, > BIOS VMW201.00V.21805430.BA64.2305221830 05/22/2023 > [ 5301.596082] pstate: 01400005 (nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) > [ 5301.596085] pc : strnlen+0x40/0x88 > [ 5301.596114] lr : trace_event_get_offsets_qdisc_reset+0x6c/0x2b0 > [ 5301.596124] sp : ffff8000beef6b40 > [ 5301.596126] x29: ffff8000beef6b40 x28: dfff800000000000 x27: 0000000000000001 > [ 5301.596131] x26: 6de1800082c62bd0 x25: 1ffff000110aa9e0 x24: ffff800088554f00 > [ 5301.596136] x23: ffff800088554ec0 x22: 0000000000000130 x21: 0000000000000140 > [ 5301.596140] x20: dfff800000000000 x19: ffff8000beef6c60 x18: ffff7000115106d8 > [ 5301.596143] x17: ffff800121bad000 x16: ffff800080020000 x15: 0000000000000006 > [ 5301.596147] x14: 0000000000000002 x13: ffff0001f3ed8d14 x12: ffff700017ddeda5 > [ 5301.596151] x11: 1ffff00017ddeda4 x10: ffff700017ddeda4 x9 : ffff800082cc5eec > [ 5301.596155] x8 : 0000000000000004 x7 : 00000000f1f1f1f1 x6 : 00000000f2f2f200 > [ 5301.596158] x5 : 00000000f3f3f3f3 x4 : ffff700017dded80 x3 : 00000000f204f1f1 > [ 5301.596162] x2 : 0000000000000026 x1 : 0000000000000000 x0 : 0000000000000130 > [ 5301.596166] Call trace: > [ 5301.596175] strnlen+0x40/0x88 > [ 5301.596179] trace_event_get_offsets_qdisc_reset+0x6c/0x2b0 > [ 5301.596182] perf_trace_qdisc_reset+0xb0/0x538 > [ 5301.596184] __traceiter_qdisc_reset+0x68/0xc0 > [ 5301.596188] qdisc_reset+0x43c/0x5e8 > [ 5301.596190] netif_set_real_num_tx_queues+0x288/0x770 > [ 5301.596194] veth_init_queues+0xfc/0x130 [veth] > [ 5301.596198] veth_newlink+0x45c/0x850 [veth] > [ 5301.596202] rtnl_newlink_create+0x2c8/0x798 > [ 5301.596205] __rtnl_newlink+0x92c/0xb60 > [ 5301.596208] rtnl_newlink+0xd8/0x130 > [ 5301.596211] rtnetlink_rcv_msg+0x2e0/0x890 > [ 5301.596214] netlink_rcv_skb+0x1c4/0x380 > [ 5301.596225] rtnetlink_rcv+0x20/0x38 > [ 5301.596227] netlink_unicast+0x3c8/0x640 > [ 5301.596231] netlink_sendmsg+0x658/0xa60 > [ 5301.596234] __sock_sendmsg+0xd0/0x180 > [ 5301.596243] __sys_sendto+0x1c0/0x280 > [ 5301.596246] __arm64_sys_sendto+0xc8/0x150 > [ 5301.596249] invoke_syscall+0xdc/0x268 > [ 5301.596256] el0_svc_common.constprop.0+0x16c/0x240 > [ 5301.596259] do_el0_svc+0x48/0x68 > [ 5301.596261] el0_svc+0x50/0x188 > [ 5301.596265] el0t_64_sync_handler+0x120/0x130 > [ 5301.596268] el0t_64_sync+0x194/0x198 > [ 5301.596272] Code: eb15001f 54000120 d343fc02 12000801 (38f46842) > [ 5301.596285] SMP: stopping secondary CPUs > [ 5301.597053] Starting crashdump kernel... > [ 5301.597057] Bye! > > Yeoreum and I don't know if the patch we wrote will fix the underlying cause, > but we think that priority is to prevent kernel panic happening. > So, we're sending this patch. > > Link: https://lore.kernel.org/lkml/20240229143432.273b4871@gandalf.local.home/t/ > Fixes: 51270d573a8d ("tracing/net_sched: Fix tracepoints that save qdisc_dev() as a string") > Cc: netdev@vger.kernel.org > Cc: stable@vger.kernel.org # +v6.7.10, +v6.8 > Signed-off-by: Yunseong Kim <yskelg@gmail.com> > Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com> > --- > include/trace/events/qdisc.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/trace/events/qdisc.h b/include/trace/events/qdisc.h > index f1b5e816e7e5..170b51fbe47a 100644 > --- a/include/trace/events/qdisc.h > +++ b/include/trace/events/qdisc.h > @@ -81,7 +81,7 @@ TRACE_EVENT(qdisc_reset, > TP_ARGS(q), > > TP_STRUCT__entry( > - __string( dev, qdisc_dev(q)->name ) > + __string(dev, qdisc_dev(q) ? qdisc_dev(q)->name : "noop_queue") > __string( kind, q->ops->id ) > __field( u32, parent ) > __field( u32, handle ) You missed the __assign_str portion (see below). Also let's just say "(null)" as it's the correct device name. "noop_queue" could be misleading. diff --git a/include/trace/events/qdisc.h b/include/trace/events/qdisc.h index 1f4258308b96..f54e0b4dbcf4 100644 --- a/include/trace/events/qdisc.h +++ b/include/trace/events/qdisc.h @@ -81,14 +81,14 @@ TRACE_EVENT(qdisc_reset, TP_ARGS(q), TP_STRUCT__entry( - __string( dev, qdisc_dev(q)->name ) + __string( dev, qdisc_dev(q) ? qdisc_dev(q)->name : "(null)" ) __string( kind, q->ops->id ) __field( u32, parent ) __field( u32, handle ) ), TP_fast_assign( - __assign_str(dev, qdisc_dev(q)->name); + __assign_str(dev, qdisc_dev(q) ? qdisc_dev(q)->name : "(null)"); __assign_str(kind, q->ops->id); __entry->parent = q->parent; __entry->handle = q->handle;
Hi Pedro, On 6/25/24 12:12 오전, Pedro Tammela wrote: > On 22/06/2024 01:57, yskelg@gmail.com wrote: >> From: Yunseong Kim <yskelg@gmail.com> >> >> In the TRACE_EVENT(qdisc_reset) NULL dereference occurred from >> >> qdisc->dev_queue->dev <NULL> ->name >> >> [ 5301.595872] KASAN: null-ptr-deref in range >> [0x0000000000000130-0x0000000000000137] >> [ 5301.595877] Mem abort info: >> [ 5301.595881] ESR = 0x0000000096000006 >> [ 5301.595885] EC = 0x25: DABT (current EL), IL = 32 bits >> [ 5301.595889] SET = 0, FnV = 0 >> [ 5301.595893] EA = 0, S1PTW = 0 >> [ 5301.595896] FSC = 0x06: level 2 translation fault >> [ 5301.595900] Data abort info: >> [ 5301.595903] ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 >> [ 5301.595907] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 >> [ 5301.595911] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 >> [ 5301.595915] [dfff800000000026] address between user and kernel >> address ranges >> [ 5301.595971] Internal error: Oops: 0000000096000006 [#1] SMP >> Link: >> https://lore.kernel.org/lkml/20240229143432.273b4871@gandalf.local.home/t/ >> Fixes: 51270d573a8d ("tracing/net_sched: Fix tracepoints that save >> qdisc_dev() as a string") >> Cc: netdev@vger.kernel.org >> Cc: stable@vger.kernel.org # +v6.7.10, +v6.8 >> Signed-off-by: Yunseong Kim <yskelg@gmail.com> >> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com> >> --- >> include/trace/events/qdisc.h | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/include/trace/events/qdisc.h b/include/trace/events/qdisc.h >> index f1b5e816e7e5..170b51fbe47a 100644 >> --- a/include/trace/events/qdisc.h >> +++ b/include/trace/events/qdisc.h >> @@ -81,7 +81,7 @@ TRACE_EVENT(qdisc_reset, >> TP_ARGS(q), >> TP_STRUCT__entry( >> - __string( dev, qdisc_dev(q)->name ) >> + __string(dev, qdisc_dev(q) ? qdisc_dev(q)->name : "noop_queue") >> __string( kind, q->ops->id ) >> __field( u32, parent ) >> __field( u32, handle ) > > You missed the __assign_str portion (see below). Also let's just say > "(null)" as it's the correct device name. "noop_queue" could be misleading. Thanks for the code review Pedro, I agree your advice. > diff --git a/include/trace/events/qdisc.h b/include/trace/events/qdisc.h > index 1f4258308b96..f54e0b4dbcf4 100644 > --- a/include/trace/events/qdisc.h > +++ b/include/trace/events/qdisc.h > @@ -81,14 +81,14 @@ TRACE_EVENT(qdisc_reset, > TP_ARGS(q), > > TP_STRUCT__entry( > - __string( dev, qdisc_dev(q)->name ) > + __string( dev, qdisc_dev(q) ? > qdisc_dev(q)->name : "(null)" ) > __string( kind, q->ops->id ) > __field( u32, parent ) > __field( u32, handle ) > ), It looks better to align the name with the current convention. Link: https://lore.kernel.org/linux-trace-kernel/20240222211442.634192653@goodmis.org/ > TP_fast_assign( > - __assign_str(dev, qdisc_dev(q)->name); > + __assign_str(dev, qdisc_dev(q) ? qdisc_dev(q)->name : > "(null)"); > __assign_str(kind, q->ops->id); > __entry->parent = q->parent; > __entry->handle = q->handle; > > The second part you mentioned, Steve recently worked on it and changed it. Link: https://lore.kernel.org/linux-trace-kernel/20240516133454.681ba6a0@rorschach.local.home/ If it hadn't, I don't think I would have been able to prevent the panic by just applying my patch. Link: https://lore.kernel.org/all/e2f9da4e-919d-4a98-919d-167726ef6bc7@gmail.com/ Warm Regards, Yunseong Kim
On 24/06/2024 12:43, Yunseong Kim wrote: > Hi Pedro, > > On 6/25/24 12:12 오전, Pedro Tammela wrote: >> On 22/06/2024 01:57, yskelg@gmail.com wrote: >>> From: Yunseong Kim <yskelg@gmail.com> >>> >>> In the TRACE_EVENT(qdisc_reset) NULL dereference occurred from >>> >>> qdisc->dev_queue->dev <NULL> ->name >>> >>> [ 5301.595872] KASAN: null-ptr-deref in range >>> [0x0000000000000130-0x0000000000000137] >>> [ 5301.595877] Mem abort info: >>> [ 5301.595881] ESR = 0x0000000096000006 >>> [ 5301.595885] EC = 0x25: DABT (current EL), IL = 32 bits >>> [ 5301.595889] SET = 0, FnV = 0 >>> [ 5301.595893] EA = 0, S1PTW = 0 >>> [ 5301.595896] FSC = 0x06: level 2 translation fault >>> [ 5301.595900] Data abort info: >>> [ 5301.595903] ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 >>> [ 5301.595907] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 >>> [ 5301.595911] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 >>> [ 5301.595915] [dfff800000000026] address between user and kernel >>> address ranges >>> [ 5301.595971] Internal error: Oops: 0000000096000006 [#1] SMP >>> Link: >>> https://lore.kernel.org/lkml/20240229143432.273b4871@gandalf.local.home/t/ >>> Fixes: 51270d573a8d ("tracing/net_sched: Fix tracepoints that save >>> qdisc_dev() as a string") >>> Cc: netdev@vger.kernel.org >>> Cc: stable@vger.kernel.org # +v6.7.10, +v6.8 >>> Signed-off-by: Yunseong Kim <yskelg@gmail.com> >>> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com> >>> --- >>> include/trace/events/qdisc.h | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/include/trace/events/qdisc.h b/include/trace/events/qdisc.h >>> index f1b5e816e7e5..170b51fbe47a 100644 >>> --- a/include/trace/events/qdisc.h >>> +++ b/include/trace/events/qdisc.h >>> @@ -81,7 +81,7 @@ TRACE_EVENT(qdisc_reset, >>> TP_ARGS(q), >>> TP_STRUCT__entry( >>> - __string( dev, qdisc_dev(q)->name ) >>> + __string(dev, qdisc_dev(q) ? qdisc_dev(q)->name : "noop_queue") >>> __string( kind, q->ops->id ) >>> __field( u32, parent ) >>> __field( u32, handle ) >> >> You missed the __assign_str portion (see below). Also let's just say >> "(null)" as it's the correct device name. "noop_queue" could be misleading. > > Thanks for the code review Pedro, I agree your advice. > >> diff --git a/include/trace/events/qdisc.h b/include/trace/events/qdisc.h >> index 1f4258308b96..f54e0b4dbcf4 100644 >> --- a/include/trace/events/qdisc.h >> +++ b/include/trace/events/qdisc.h >> @@ -81,14 +81,14 @@ TRACE_EVENT(qdisc_reset, >> TP_ARGS(q), >> >> TP_STRUCT__entry( >> - __string( dev, qdisc_dev(q)->name ) >> + __string( dev, qdisc_dev(q) ? >> qdisc_dev(q)->name : "(null)" ) >> __string( kind, q->ops->id ) >> __field( u32, parent ) >> __field( u32, handle ) >> ), > > It looks better to align the name with the current convention. > > Link: > https://lore.kernel.org/linux-trace-kernel/20240222211442.634192653@goodmis.org/ > >> TP_fast_assign( >> - __assign_str(dev, qdisc_dev(q)->name); >> + __assign_str(dev, qdisc_dev(q) ? qdisc_dev(q)->name : >> "(null)"); >> __assign_str(kind, q->ops->id); >> __entry->parent = q->parent; >> __entry->handle = q->handle; >> >> > > The second part you mentioned, Steve recently worked on it and changed it. > > Link: > https://lore.kernel.org/linux-trace-kernel/20240516133454.681ba6a0@rorschach.local.home/ Oh! > > If it hadn't, I don't think I would have been able to prevent the panic > by just applying my patch. But you must be careful with the backports. In any case, perhaps send another patch to net-next updating the new conventions there and use the 'old convention' for the bug fix?
Hi Pedro, On 6/25/24 12:55 오전, Pedro Tammela wrote: > On 24/06/2024 12:43, Yunseong Kim wrote: >> Hi Pedro, >> >> On 6/25/24 12:12 오전, Pedro Tammela wrote: >>> On 22/06/2024 01:57, yskelg@gmail.com wrote: >>>> From: Yunseong Kim <yskelg@gmail.com> >>>> >>>> In the TRACE_EVENT(qdisc_reset) NULL dereference occurred from >>>> >>>> qdisc->dev_queue->dev <NULL> ->name >>>> >>>> [ 5301.595872] KASAN: null-ptr-deref in range >>>> [0x0000000000000130-0x0000000000000137] >>>> [ 5301.595877] Mem abort info: >>>> [ 5301.595881] ESR = 0x0000000096000006 >>>> [ 5301.595885] EC = 0x25: DABT (current EL), IL = 32 bits >>>> [ 5301.595889] SET = 0, FnV = 0 >>>> [ 5301.595893] EA = 0, S1PTW = 0 >>>> [ 5301.595896] FSC = 0x06: level 2 translation fault >>>> [ 5301.595900] Data abort info: >>>> [ 5301.595903] ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 >>>> [ 5301.595907] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 >>>> [ 5301.595911] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 >>>> [ 5301.595915] [dfff800000000026] address between user and kernel >>>> address ranges >>>> [ 5301.595971] Internal error: Oops: 0000000096000006 [#1] SMP >>>> Link: >>>> https://lore.kernel.org/lkml/20240229143432.273b4871@gandalf.local.home/t/ >>>> Fixes: 51270d573a8d ("tracing/net_sched: Fix tracepoints that save >>>> qdisc_dev() as a string") >>>> Cc: netdev@vger.kernel.org >>>> Cc: stable@vger.kernel.org # +v6.7.10, +v6.8 >>>> Signed-off-by: Yunseong Kim <yskelg@gmail.com> >>>> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com> >>>> --- >>>> include/trace/events/qdisc.h | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/include/trace/events/qdisc.h >>>> b/include/trace/events/qdisc.h >>>> index f1b5e816e7e5..170b51fbe47a 100644 >>>> --- a/include/trace/events/qdisc.h >>>> +++ b/include/trace/events/qdisc.h >>>> @@ -81,7 +81,7 @@ TRACE_EVENT(qdisc_reset, >>>> TP_ARGS(q), >>>> TP_STRUCT__entry( >>>> - __string( dev, qdisc_dev(q)->name ) >>>> + __string(dev, qdisc_dev(q) ? qdisc_dev(q)->name : >>>> "noop_queue") >>>> __string( kind, q->ops->id ) >>>> __field( u32, parent ) >>>> __field( u32, handle ) >>> >>> You missed the __assign_str portion (see below). Also let's just say >>> "(null)" as it's the correct device name. "noop_queue" could be >>> misleading. >> >> Thanks for the code review Pedro, I agree your advice. >> >>> diff --git a/include/trace/events/qdisc.h b/include/trace/events/qdisc.h >>> index 1f4258308b96..f54e0b4dbcf4 100644 >>> --- a/include/trace/events/qdisc.h >>> +++ b/include/trace/events/qdisc.h >>> @@ -81,14 +81,14 @@ TRACE_EVENT(qdisc_reset, >>> TP_ARGS(q), >>> >>> TP_STRUCT__entry( >>> - __string( dev, >>> qdisc_dev(q)->name ) >>> + __string( dev, qdisc_dev(q) ? >>> qdisc_dev(q)->name : "(null)" ) >>> __string( kind, >>> q->ops->id ) >>> __field( u32, >>> parent ) >>> __field( u32, >>> handle ) >>> ), >> >> It looks better to align the name with the current convention. >> >> Link: >> https://lore.kernel.org/linux-trace-kernel/20240222211442.634192653@goodmis.org/ >> >>> TP_fast_assign( >>> - __assign_str(dev, qdisc_dev(q)->name); >>> + __assign_str(dev, qdisc_dev(q) ? qdisc_dev(q)->name : >>> "(null)"); >>> __assign_str(kind, q->ops->id); >>> __entry->parent = q->parent; >>> __entry->handle = q->handle; >>> >>> >> >> The second part you mentioned, Steve recently worked on it and changed >> it. >> >> Link: >> https://lore.kernel.org/linux-trace-kernel/20240516133454.681ba6a0@rorschach.local.home/ > > Oh! Thanks for the double check, Pedro. >> If it hadn't, I don't think I would have been able to prevent the panic >> by just applying my patch. > > But you must be careful with the backports. > > In any case, perhaps send another patch to net-next updating the new > conventions there and use the 'old convention' for the bug fix? Right, I agree, I'll send a patch for the next version. Warm regards, Yunseong Kim
diff --git a/include/trace/events/qdisc.h b/include/trace/events/qdisc.h index f1b5e816e7e5..170b51fbe47a 100644 --- a/include/trace/events/qdisc.h +++ b/include/trace/events/qdisc.h @@ -81,7 +81,7 @@ TRACE_EVENT(qdisc_reset, TP_ARGS(q), TP_STRUCT__entry( - __string( dev, qdisc_dev(q)->name ) + __string(dev, qdisc_dev(q) ? qdisc_dev(q)->name : "noop_queue") __string( kind, q->ops->id ) __field( u32, parent ) __field( u32, handle )