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| author | Qun-Wei Lin <qun-wei.lin@mediatek.com> | 2024-10-25 11:58:11 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-11-17 17:08:58 +0300 |
| commit | 71548fada7ee0eb50cc6ccda82dff010c745f92c (patch) | |
| tree | d886651248041ca0ac618e4dd1c2ad3650f10ca9 /mm | |
| parent | 950ac86cff338ab56e2eaf611f4936ee34893b63 (diff) | |
| download | linux-71548fada7ee0eb50cc6ccda82dff010c745f92c.tar.xz | |
mm: krealloc: Fix MTE false alarm in __do_krealloc
commit 704573851b51808b45dae2d62059d1d8189138a2 upstream.
This patch addresses an issue introduced by commit 1a83a716ec233 ("mm:
krealloc: consider spare memory for __GFP_ZERO") which causes MTE
(Memory Tagging Extension) to falsely report a slab-out-of-bounds error.
The problem occurs when zeroing out spare memory in __do_krealloc. The
original code only considered software-based KASAN and did not account
for MTE. It does not reset the KASAN tag before calling memset, leading
to a mismatch between the pointer tag and the memory tag, resulting
in a false positive.
Example of the error:
==================================================================
swapper/0: BUG: KASAN: slab-out-of-bounds in __memset+0x84/0x188
swapper/0: Write at addr f4ffff8005f0fdf0 by task swapper/0/1
swapper/0: Pointer tag: [f4], memory tag: [fe]
swapper/0:
swapper/0: CPU: 4 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.
swapper/0: Hardware name: MT6991(ENG) (DT)
swapper/0: Call trace:
swapper/0: dump_backtrace+0xfc/0x17c
swapper/0: show_stack+0x18/0x28
swapper/0: dump_stack_lvl+0x40/0xa0
swapper/0: print_report+0x1b8/0x71c
swapper/0: kasan_report+0xec/0x14c
swapper/0: __do_kernel_fault+0x60/0x29c
swapper/0: do_bad_area+0x30/0xdc
swapper/0: do_tag_check_fault+0x20/0x34
swapper/0: do_mem_abort+0x58/0x104
swapper/0: el1_abort+0x3c/0x5c
swapper/0: el1h_64_sync_handler+0x80/0xcc
swapper/0: el1h_64_sync+0x68/0x6c
swapper/0: __memset+0x84/0x188
swapper/0: btf_populate_kfunc_set+0x280/0x3d8
swapper/0: __register_btf_kfunc_id_set+0x43c/0x468
swapper/0: register_btf_kfunc_id_set+0x48/0x60
swapper/0: register_nf_nat_bpf+0x1c/0x40
swapper/0: nf_nat_init+0xc0/0x128
swapper/0: do_one_initcall+0x184/0x464
swapper/0: do_initcall_level+0xdc/0x1b0
swapper/0: do_initcalls+0x70/0xc0
swapper/0: do_basic_setup+0x1c/0x28
swapper/0: kernel_init_freeable+0x144/0x1b8
swapper/0: kernel_init+0x20/0x1a8
swapper/0: ret_from_fork+0x10/0x20
==================================================================
Fixes: 1a83a716ec233 ("mm: krealloc: consider spare memory for __GFP_ZERO")
Signed-off-by: Qun-Wei Lin <qun-wei.lin@mediatek.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/slab_common.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/slab_common.c b/mm/slab_common.c index ef971fcdaa07..2e2b43fae2c3 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -1391,7 +1391,7 @@ __do_krealloc(const void *p, size_t new_size, gfp_t flags) /* Zero out spare memory. */ if (want_init_on_alloc(flags)) { kasan_disable_current(); - memset((void *)p + new_size, 0, ks - new_size); + memset(kasan_reset_tag(p) + new_size, 0, ks - new_size); kasan_enable_current(); } |