I don't know this code well enough to give a meaningful OK, but this
should probably get committed.


On 2022/06/01 09:16, Alexandr Nedvedicky wrote:
> Hello,
> 
> </snip>
> > r420-1# rcctl -f start relayd
> > relayd(ok)
> > r420-1# uvm_fault(0xfffffd862f82f990, 0x0, 0, 1) -> e
> > kernel: page fault trap, code=0
> > Stopped at      pf_find_or_create_ruleset+0x1c: movb    0(%rdi),%al
> >     TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
> >  431388  19003      0         0x2          0    5  relayd
> >  174608  32253     89   0x1000012          0    2  relayd
> >  395415  12468      0         0x2          0    4  relayd
> >  493579  11904      0         0x2          0    3  relayd
> > *101082  14967     89   0x1100012          0    0K relayd
> > pf_find_or_create_ruleset(0) at pf_find_or_create_ruleset+0x1c
> > pfr_add_tables(832d7cca800,1,ffff800000eaf43c,10000000) at
> > pfr_add_tables+0x6ae
> > 
> > pfioctl(4900,c450443d,ffff800000eaf000,3,ffff80002272e7f0) at pfioctl+0x1d9f
> > VOP_IOCTL(fffffd8551f82dd0,c450443d,ffff800000eaf000,3,fffffd862f7d60c0,ffff800
> > 02272e7f0) at VOP_IOCTL+0x5c
> > vn_ioctl(fffffd855ecec1e8,c450443d,ffff800000eaf000,ffff80002272e7f0) at
> > vn_ioctl+0x75
> > sys_ioctl(ffff80002272e7f0,ffff8000227d9980,ffff8000227d99d0) at
> > sys_ioctl+0x2c4
> > syscall(ffff8000227d9a40) at syscall+0x374
> > Xsyscall() at Xsyscall+0x128
> > end of kernel
> 
>     it looks like we are dying here at line 239 due to NULL pointer deference:
> 
> 232 struct pf_ruleset *
> 233 pf_find_or_create_ruleset(const char *path)
> 234 {
> 235         char                    *p, *aname, *r;
> 236         struct pf_ruleset       *ruleset;
> 237         struct pf_anchor        *anchor;
> 238 
> 239         if (path[0] == 0)
> 240                 return (&pf_main_ruleset);
> 241 
> 242         while (*path == '/')
> 243                 path++;
> 244 
> 
>     I've followed the same steps to reproduce the issue to check if
>     diff below resolves the issue. The bug has been introduced by
>     my recent change to pf_table.c [1] from May 10th:
> 
>       Modified files:
>               sys/net        : pf_ioctl.c pf_table.c 
> 
>       Log message:
>       move memory allocations in pfr_add_tables() out of
>       NET_LOCK()/PF_LOCK() scope. bluhm@ helped a lot
>       to put this diff into shape.
> 
> besides using a regression test I've also did simple testing
> using a 'load anchor':
> 
>     netlock# cat /tmp/anchor.conf                                             
>      
>     load anchor "test" from "/tmp/pf.conf"
>     netlock#
>     netlock# cat /tmp/pf.conf                                                 
>      
>     table <try> { 192.168.1.1 }
>     pass from <try>
>     netlock#
>     netlock# pfctl -sA
>       test
>     netlock# pfctl -a test -sT
>     try
>     netlock# pfctl -a test -t try -T show
>        192.168.1.1
> 
> OK to commit fix below?
> 
> thanks and
> regards
> sashan
> 
> [1] https://marc.info/?l=openbsd-cvs&m=165222430111103&w=2
> 
> --------8<---------------8<---------------8<------------------8<--------
> diff --git a/sys/net/pf_table.c b/sys/net/pf_table.c
> index 8315ea5dd3a..dfc49de5efe 100644
> --- a/sys/net/pf_table.c
> +++ b/sys/net/pf_table.c
> @@ -1628,8 +1628,7 @@ pfr_add_tables(struct pfr_table *tbl, int size, int 
> *nadd, int flags)
>                       if (r != NULL)
>                               continue;
>  
> -                     q->pfrkt_rs = pf_find_or_create_ruleset(
> -                         q->pfrkt_root->pfrkt_anchor);
> +                     q->pfrkt_rs = 
> pf_find_or_create_ruleset(q->pfrkt_anchor);
>                       /*
>                        * root tables are attached to main ruleset,
>                        * because ->pfrkt_anchor[0] == '\0'
> 

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