FreeBSD lock order reversal (LOR) #268

lock order reversal:
 1st 0xc09ca828 ifnet (ifnet) @ sys/net/if.c:849
 2nd 0xc45d604c pf task mtx (pf task mtx) @ sys/modules/pf/../../contrib/pf/net/pf_if.c:916
		
KDB: stack backtrace:
db_trace_self_wrapper(c08df797,fb671764,c0630e8e,c08e1c96,c45d604c,...) at db_trace_self_wrapper+0x26
kdb_backtrace(c08e1c96,c45d604c,c45d3b1c,c45d3b1c,c45d379e,...) at kdb_backtrace+0x29
witness_checkorder(c45d604c,9,c45d379e,394,c08e9058,...) at witness_checkorder+0x6de
_mtx_lock_flags(c45d604c,0,c45d379e,394,fb6717dc,...) at _mtx_lock_flags+0xbc
pfi_attach_group_event(0,c4450000,c08e9058,374,c44a920c,...) at pfi_attach_group_event+0x4e
if_addgroup(c441c000,c08f70d6,4,0,0,...) at if_addgroup+0x2c7
if_clone_createif(0,0,c08e9563,87,0,...) at if_clone_createif+0x81
if_clone_create(fb671943,4,0,44,180,...) at if_clone_create+0x8c
tunclone(0,c461e400,fb671943,4,fb67195c,...) at tunclone+0x17a
devfs_lookup(fb6719d0,fb6719d0,fb671b7c,c418de04,2,...) at devfs_lookup+0x50e
VOP_LOOKUP_APV(c0928f40,fb6719d0,c412f230,c08e77ef,2a9,...) at VOP_LOOKUP_APV+0xa5
lookup(fb671b7c,c08e77ef,c6,bf,c461e92c,...) at lookup+0x58e
namei(fb671b7c,c412f230,fb671a74,246,c0983774,...) at namei+0x34b
vn_open_cred(fb671b7c,fb671c78,ce8,c461e400,c4460558,...) at vn_open_cred+0x2c9
vn_open(fb671b7c,fb671c78,ce8,c4460558,c05e807d,...) at vn_open+0x33
kern_open(c412f230,80a0f18,0,3,808ecfa,...) at kern_open+0xe7
open(c412f230,fb671cfc,c,c08e28c3,c092c0b8,...) at open+0x30
syscall(fb671d38) at syscall+0x2b3
Xint0x80_syscall() at Xint0x80_syscall+0x20
--- syscall (5, FreeBSD ELF32, open), eip = 0x2835a65b, esp = 0xbfbfeafc, ebp = 0xbfbfeb38 ---
		

• freebsd-stable (thread)