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| author | Li Qiong <liqiong@nfschina.com> | 2025-09-06 21:17:23 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-09-09 18:56:29 +0200 |
| commit | 0ef7058b4dc6fcef622ac23b45225db57f17b83f (patch) | |
| tree | 8da12479448c9a168a506e8235abad3d2423b459 /mm | |
| parent | ba0ccc1be52c5b9b82f268113e5db924293d3288 (diff) | |
| download | linux-0ef7058b4dc6fcef622ac23b45225db57f17b83f.tar.gz linux-0ef7058b4dc6fcef622ac23b45225db57f17b83f.tar.bz2 linux-0ef7058b4dc6fcef622ac23b45225db57f17b83f.zip | |
mm/slub: avoid accessing metadata when pointer is invalid in object_err()
[ Upstream commit b4efccec8d06ceb10a7d34d7b1c449c569d53770 ]
object_err() reports details of an object for further debugging, such as
the freelist pointer, redzone, etc. However, if the pointer is invalid,
attempting to access object metadata can lead to a crash since it does
not point to a valid object.
One known path to the crash is when alloc_consistency_checks()
determines the pointer to the allocated object is invalid because of a
freelist corruption, and calls object_err() to report it. The debug code
should report and handle the corruption gracefully and not crash in the
process.
In case the pointer is NULL or check_valid_pointer() returns false for
the pointer, only print the pointer value and skip accessing metadata.
Fixes: 81819f0fc828 ("SLUB core")
Cc: <stable@vger.kernel.org>
Signed-off-by: Li Qiong <liqiong@nfschina.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
[ Adjust context ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/slub.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/mm/slub.c b/mm/slub.c index d2544c88a5c4..391f9db1c8f3 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -988,7 +988,12 @@ static void object_err(struct kmem_cache *s, struct slab *slab, return; slab_bug(s, "%s", reason); - print_trailer(s, slab, object); + if (!object || !check_valid_pointer(s, slab, object)) { + print_slab_info(slab); + pr_err("Invalid pointer 0x%p\n", object); + } else { + print_trailer(s, slab, object); + } add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); } |