Observed at boot time:
CPU: 43 UID: 0 PID: 3595 Comm: (t-daemon) Not tainted 6.12.0 #1
Call Trace:
<TASK>
dump_stack_lvl+0x4e/0x70
pcpu_alloc_noprof.cold+0x1f/0x4b
fib_nh_common_init+0x4c/0x110
fib6_nh_init+0x387/0x740
ip6_route_info_create+0x46d/0x640
addrconf_f6i_alloc+0x13b/0x180
addrconf_permanent_addr+0xd0/0x220
addrconf_notify+0x93/0x540
notifier_call_chain+0x5a/0xd0
__dev_notify_flags+0x5c/0xf0
dev_change_flags+0x54/0x70
do_setlink+0x36c/0xce0
rtnl_setlink+0x11f/0x1d0
rtnetlink_rcv_msg+0x142/0x3f0
netlink_rcv_skb+0x50/0x100
netlink_unicast+0x242/0x390
netlink_sendmsg+0x21b/0x470
__sys_sendto+0x1dc/0x1f0
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x7d/0x160
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f5c3852f127
Code: 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 80 3d 85 ef 0c 00 00 41 89 ca 74 10 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 71 c3 55 48 83 ec 30 44 89 4c 24 2c 4c 89 44
RSP: 002b:00007ffe86caf4c8 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000556c5cd93210 RCX: 00007f5c3852f127
RDX: 0000000000000020 RSI: 0000556c5cd938b0 RDI: 0000000000000003
RBP: 00007ffe86caf5a0 R08: 00007ffe86caf4e0 R09: 0000000000000080
R10: 0000000000000000 R11: 0000000000000202 R12: 0000556c5cd932d0
R13: 00000000021d05d1 R14: 00000000021d05d1 R15: 0000000000000001
IFA_F_PERMANENT addresses require the allocation of a bunch of percpu
pointers, currently in atomic scope.
Similar to commit 51454ea42c ("ipv6: fix locking issues with loops
over idev->addr_list"), move fixup_permanent_addr() outside the
&idev->lock scope, and do the allocations with GFP_KERNEL. With such
change fixup_permanent_addr() is invoked with the BH enabled, and the
ifp lock acquired there needs the BH variant.
Note that we don't need to acquire a reference to the permanent
addresses before releasing the mentioned write lock, because
addrconf_permanent_addr() runs under RTNL and ifa removal always happens
under RTNL, too.
Also the PERMANENT flag is constant in the relevant scope, as it can be
cleared only by inet6_addr_modify() under the RTNL lock.
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/46a7a030727e236af2dc7752994cd4f04f4a91d2.1775658924.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
8e6405f821