4:36 p.m.
tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head: ec2618180c3450d06a6a4ba951d4c9a2c689b517
commit: e2d5b2bb769fa5f500760caba76436ba3a10a895 [2296/2770] bpf: Fix nested
bpf_bprintf_prepare with more per-cpu buffers
compiler: sparc64-linux-gcc (GCC) 9.3.0
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp(a)intel.com>
cppcheck possible warnings: (new ones prefixed by >>, may not real problems)
> kernel/bpf/helpers.c:713:43: warning: Uninitialized variable:
bufs [uninitvar]
if (WARN_ON_ONCE(nest_level >
ARRAY_SIZE(bufs->tmp_bufs))) {
^
kernel/bpf/helpers.c:408:20: warning: Possible null pointer dereference: storage
[nullPointer]
ptr = &READ_ONCE(storage->buf)->data[0];
^
kernel/bpf/helpers.c:395:39: note: Assignment 'storage=NULL', assigned value is
0
struct bpf_cgroup_storage *storage = NULL;
^
kernel/bpf/helpers.c:408:20: note: Null pointer dereference
ptr = &READ_ONCE(storage->buf)->data[0];
^
vim +713 kernel/bpf/helpers.c
d9c9e4db186ab4 Florent Revest 2021-04-19 705
d9c9e4db186ab4 Florent Revest 2021-04-19 706 static int try_get_fmt_tmp_buf(char
**tmp_buf)
d9c9e4db186ab4 Florent Revest 2021-04-19 707 {
e2d5b2bb769fa5 Florent Revest 2021-05-11 708 struct bpf_bprintf_buffers *bufs;
e2d5b2bb769fa5 Florent Revest 2021-05-11 709 int nest_level;
d9c9e4db186ab4 Florent Revest 2021-04-19 710
d9c9e4db186ab4 Florent Revest 2021-04-19 711 preempt_disable();
e2d5b2bb769fa5 Florent Revest 2021-05-11 712 nest_level =
this_cpu_inc_return(bpf_bprintf_nest_level);
e2d5b2bb769fa5 Florent Revest 2021-05-11 @713 if (WARN_ON_ONCE(nest_level >
ARRAY_SIZE(bufs->tmp_bufs))) {
e2d5b2bb769fa5 Florent Revest 2021-05-11 714 this_cpu_dec(bpf_bprintf_nest_level);
d9c9e4db186ab4 Florent Revest 2021-04-19 715 preempt_enable();
d9c9e4db186ab4 Florent Revest 2021-04-19 716 return -EBUSY;
d9c9e4db186ab4 Florent Revest 2021-04-19 717 }
e2d5b2bb769fa5 Florent Revest 2021-05-11 718 bufs =
this_cpu_ptr(&bpf_bprintf_bufs);
e2d5b2bb769fa5 Florent Revest 2021-05-11 719 *tmp_buf = bufs->tmp_bufs[nest_level -
1];
d9c9e4db186ab4 Florent Revest 2021-04-19 720
d9c9e4db186ab4 Florent Revest 2021-04-19 721 return 0;
d9c9e4db186ab4 Florent Revest 2021-04-19 722 }
d9c9e4db186ab4 Florent Revest 2021-04-19 723
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