BUG: sleeping function called from invalid context at include/linux/sched/mm.h:209
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 3962, name: syz-executor223
2 locks held by syz-executor223/3962:
#0: ffff8000169e7228 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff8000169e7228 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5596
#1: ffff0000cb9c9108 (&sch->q.lock){+...}-{2:2}, at: netem_change+0x22c/0x1a90 net/sched/sch_netem.c:972
Preemption disabled at:
[<ffff800010046d84>] netem_change+0x22c/0x1a90 net/sched/sch_netem.c:972
CPU: 1 PID: 3962 Comm: syz-executor223 Not tainted 5.15.124-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
Call trace:
dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
dump_stack+0x1c/0x58 lib/dump_stack.c:113
___might_sleep+0x380/0x4dc kernel/sched/core.c:9625
__might_sleep+0x98/0xf0 kernel/sched/core.c:9579
might_alloc include/linux/sched/mm.h:209 [inline]
slab_pre_alloc_hook+0x58/0xe8 mm/slab.h:492
slab_alloc_node mm/slub.c:3134 [inline]
__kmalloc_node+0xbc/0x5b8 mm/slub.c:4451
kmalloc_node include/linux/slab.h:614 [inline]
kvmalloc_node+0x88/0x204 mm/util.c:619
kvmalloc include/linux/mm.h:805 [inline]
get_dist_table+0x9c/0x2a4 net/sched/sch_netem.c:788
netem_change+0x7cc/0x1a90 net/sched/sch_netem.c:988
netem_init+0x54/0xb8 net/sched/sch_netem.c:1075
qdisc_create+0x6fc/0xf44 net/sched/sch_api.c:1264
tc_modify_qdisc+0x8dc/0x1344
rtnetlink_rcv_msg+0xa74/0xdac net/core/rtnetlink.c:5599
netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2505
rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:5617
netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
netlink_unicast+0x664/0x938 net/netlink/af_netlink.c:1356
netlink_sendmsg+0x844/0xb38 net/netlink/af_netlink.c:1924
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg net/socket.c:724 [inline]
____sys_sendmsg+0x584/0x870 net/socket.c:2412
___sys_sendmsg+0x214/0x294 net/socket.c:2466
__sys_sendmsg net/socket.c:2495 [inline]
__do_sys_sendmsg net/socket.c:2504 [inline]
__se_sys_sendmsg net/socket.c:2502 [inline]
__arm64_sys_sendmsg+0x1ac/0x25c net/socket.c:2502
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:596
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
============================================
WARNING: possible recursive locking detected
5.15.124-syzkaller #0 Tainted: G W
--------------------------------------------
syz-executor223/3962 is trying to acquire lock:
ffff0000cb9c9108 (&sch->q.lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
ffff0000cb9c9108 (&sch->q.lock){+...}-{2:2}, at: get_dist_table+0x1f0/0x2a4 net/sched/sch_netem.c:798
but task is already holding lock:
ffff0000cb9c9108 (&sch->q.lock){+...}-{2:2}, at: netem_change+0x22c/0x1a90 net/sched/sch_netem.c:972
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&sch->q.lock);
lock(&sch->q.lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syz-executor223/3962:
#0: ffff8000169e7228 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff8000169e7228 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5596
#1: ffff0000cb9c9108 (&sch->q.lock){+...}-{2:2}, at: netem_change+0x22c/0x1a90 net/sched/sch_netem.c:972
stack backtrace:
CPU: 1 PID: 3962 Comm: syz-executor223 Tainted: G W 5.15.124-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
Call trace:
dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
dump_stack+0x1c/0x58 lib/dump_stack.c:113
__lock_acquire+0x62b4/0x7620 kernel/locking/lockdep.c:5011
lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5622
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x124/0x1c4 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:368 [inline]
get_dist_table+0x1f0/0x2a4 net/sched/sch_netem.c:798
netem_change+0x7cc/0x1a90 net/sched/sch_netem.c:988
netem_init+0x54/0xb8 net/sched/sch_netem.c:1075
qdisc_create+0x6fc/0xf44 net/sched/sch_api.c:1264
tc_modify_qdisc+0x8dc/0x1344
rtnetlink_rcv_msg+0xa74/0xdac net/core/rtnetlink.c:5599
netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2505
rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:5617
netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
netlink_unicast+0x664/0x938 net/netlink/af_netlink.c:1356
netlink_sendmsg+0x844/0xb38 net/netlink/af_netlink.c:1924
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg net/socket.c:724 [inline]
____sys_sendmsg+0x584/0x870 net/socket.c:2412
___sys_sendmsg+0x214/0x294 net/socket.c:2466
__sys_sendmsg net/socket.c:2495 [inline]
__do_sys_sendmsg net/socket.c:2504 [inline]
__se_sys_sendmsg net/socket.c:2502 [inline]
__arm64_sys_sendmsg+0x1ac/0x25c net/socket.c:2502
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:596
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584