diff options
| author | zijun_hu <zijun_hu@htc.com> | 2016-08-04 15:32:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-08-04 20:02:09 -0400 |
| commit | e47608ab6dbe63fefe60c211a30b3fc78a1b5d5e (patch) | |
| tree | e1b92f9ab8517f8be2f4faf673b97606acb5584a | |
| parent | 4b16b0c0bf416de61d14ac31703883d76395ed5f (diff) | |
mm/memblock.c: fix NULL dereference error
It causes NULL dereference error and failure to get type_a->regions[0]
info if parameter type_b of __next_mem_range_rev() == NULL
Fix this by checking before dereferring and initializing idx_b to 0
The approach is tested by dumping all types of region via
__memblock_dump_all() and __next_mem_range_rev() fixed to UART
separately the result is okay after checking the logs.
Link: http://lkml.kernel.org/r/57A0320D.6070102@zoho.com
Signed-off-by: zijun_hu <zijun_hu@htc.com>
Tested-by: zijun_hu <zijun_hu@htc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/memblock.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/mm/memblock.c b/mm/memblock.c index 1f065da87327..483197ef613f 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -994,7 +994,10 @@ void __init_memblock __next_mem_range_rev(u64 *idx, int nid, ulong flags, if (*idx == (u64)ULLONG_MAX) { idx_a = type_a->cnt - 1; - idx_b = type_b->cnt; + if (type_b != NULL) + idx_b = type_b->cnt; + else + idx_b = 0; } for (; idx_a >= 0; idx_a--) { |