diff options
| author | Ran Xiaokai <ran.xiaokai@zte.com.cn> | 2025-09-26 08:06:59 +0000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-09-28 11:51:33 -0700 |
| commit | fb552b2425cf8f16c9c72229a972d1744b24d855 (patch) | |
| tree | f5c4dfded01257d7809dfbf44fe9f541a11576f3 | |
| parent | 989c2f55ca4839121cbf23b5802f8513dbd54e1e (diff) | |
alloc_tag: fix boot failure due to NULL pointer dereference
There is a boot failure when both CONFIG_DEBUG_KMEMLEAK and
CONFIG_MEM_ALLOC_PROFILING are enabled.
BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:__alloc_tagging_slab_alloc_hook+0x181/0x2f0
Call Trace:
kmem_cache_alloc_noprof+0x1c8/0x5c0
__alloc_object+0x2f/0x290
__create_object+0x22/0x80
kmemleak_init+0x122/0x190
mm_core_init+0xb6/0x160
start_kernel+0x39f/0x920
x86_64_start_reservations+0x18/0x30
x86_64_start_kernel+0x104/0x120
common_startup_64+0x12c/0x138
In kmemleak, mem_pool_alloc() directly calls kmem_cache_alloc_noprof(), as
a result, current->alloc_tag is NULL, leading to a null pointer
dereference.
Move the checks for SLAB_NO_OBJ_EXT, SLAB_NOLEAKTRACE, and
__GFP_NO_OBJ_EXT to the parent function __alloc_tagging_slab_alloc_hook()
to fix this.
Also this distinguishes the SLAB_NOLEAKTRACE case between the actual
memory allocation failures case, make CODETAG_FLAG_INACCURATE more
accurate.
Link: https://lkml.kernel.org/r/20250926080659.741991-1-ranxiaokai627@163.com
Fixes: b9e2f58ffb84 ("alloc_tag: mark inaccurate allocation counters in /proc/allocinfo output")
Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Cc: Christoph Lameter (Ampere) <cl@gentwo.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Usama Arif <usamaarif642@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | mm/slub.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/mm/slub.c b/mm/slub.c index 9c04f29ee8de..9d73cca9f1de 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2109,15 +2109,6 @@ prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p) { struct slab *slab; - if (!p) - return NULL; - - if (s->flags & (SLAB_NO_OBJ_EXT | SLAB_NOLEAKTRACE)) - return NULL; - - if (flags & __GFP_NO_OBJ_EXT) - return NULL; - slab = virt_to_slab(p); if (!slab_obj_exts(slab) && alloc_slab_obj_exts(slab, s, flags, false)) { @@ -2135,6 +2126,15 @@ __alloc_tagging_slab_alloc_hook(struct kmem_cache *s, void *object, gfp_t flags) { struct slabobj_ext *obj_exts; + if (!object) + return; + + if (s->flags & (SLAB_NO_OBJ_EXT | SLAB_NOLEAKTRACE)) + return; + + if (flags & __GFP_NO_OBJ_EXT) + return; + obj_exts = prepare_slab_obj_exts_hook(s, flags, object); /* * Currently obj_exts is used only for allocation profiling. |