Re: [syzbot] [mm?] KASAN: slab-use-after-free Read in mas_next_entry

From: syzbot
Date: Fri Apr 07 2023 - 12:37:15 EST

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In reply to: syzbot: "[syzbot] [mm?] KASAN: slab-use-after-free Read in mas_next_entry"
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syzbot has found a reproducer for the following issue on:

HEAD commit: f2afccfefe7b Merge tag 'net-6.3-rc6-2' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1642b49bc80000
kernel config: https://syzkaller.appspot.com/x/.config?x=d3500b143c204867
dashboard link: https://syzkaller.appspot.com/bug?extid=a7c1ec5b1d71ceaa5186
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1033df79c80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/4c6e0baeb7c2/disk-f2afccfe.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/82431f1611cf/vmlinux-f2afccfe.xz
kernel image: https://storage.googleapis.com/syzbot-assets/82e1059905ee/bzImage-f2afccfe.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a7c1ec5b1d71ceaa5186@xxxxxxxxxxxxxxxxxxxxxxxxx

==================================================================
BUG: KASAN: slab-use-after-free in mas_safe_min lib/maple_tree.c:727 [inline]
BUG: KASAN: slab-use-after-free in mas_next_nentry lib/maple_tree.c:4664 [inline]
BUG: KASAN: slab-use-after-free in mas_next_entry+0x12b3/0x1690 lib/maple_tree.c:4760
Read of size 8 at addr ffff8880782e0440 by task syz-executor.3/5331

CPU: 0 PID: 5331 Comm: syz-executor.3 Not tainted 6.3.0-rc5-syzkaller-00137-gf2afccfefe7b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:319
print_report mm/kasan/report.c:430 [inline]
kasan_report+0x11c/0x130 mm/kasan/report.c:536
mas_safe_min lib/maple_tree.c:727 [inline]
mas_next_nentry lib/maple_tree.c:4664 [inline]
mas_next_entry+0x12b3/0x1690 lib/maple_tree.c:4760
mas_find+0x7d/0x200 lib/maple_tree.c:6025
vma_find include/linux/mm.h:736 [inline]
__do_sys_set_mempolicy_home_node+0x1ef/0x480 mm/mempolicy.c:1524
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f730dc8c169
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f730ea05168 EFLAGS: 00000246 ORIG_RAX: 00000000000001c2
RAX: ffffffffffffffda RBX: 00007f730ddabf80 RCX: 00007f730dc8c169
RDX: 0000000000000000 RSI: 0000000000003000 RDI: 0000000020ffd000
RBP: 00007f730dce7ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f730decfb1f R14: 00007f730ea05300 R15: 0000000000022000
</TASK>

Allocated by task 5335:
kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
__kasan_slab_alloc+0x7f/0x90 mm/kasan/common.c:328
kasan_slab_alloc include/linux/kasan.h:186 [inline]
slab_post_alloc_hook mm/slab.h:769 [inline]
kmem_cache_alloc_bulk+0x424/0x860 mm/slub.c:4034
mt_alloc_bulk lib/maple_tree.c:164 [inline]
mas_alloc_nodes+0x276/0x8a0 lib/maple_tree.c:1263
mas_node_count_gfp lib/maple_tree.c:1318 [inline]
mas_preallocate+0x1bb/0x360 lib/maple_tree.c:5717
vma_iter_prealloc mm/internal.h:972 [inline]
__split_vma+0x1b7/0x810 mm/mmap.c:2177
do_vmi_align_munmap+0x34a/0xf60 mm/mmap.c:2320
do_vmi_munmap+0x26e/0x2c0 mm/mmap.c:2452
mmap_region+0x1ee/0x2620 mm/mmap.c:2500
do_mmap+0x831/0xf60 mm/mmap.c:1364
vm_mmap_pgoff+0x1af/0x280 mm/util.c:542
ksys_mmap_pgoff+0x41f/0x5a0 mm/mmap.c:1410
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 5331:
kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:521
____kasan_slab_free mm/kasan/common.c:236 [inline]
____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200
kasan_slab_free include/linux/kasan.h:162 [inline]
slab_free_hook mm/slub.c:1781 [inline]
slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807
slab_free mm/slub.c:3787 [inline]
kmem_cache_free_bulk.part.0+0x20c/0x680 mm/slub.c:3905
mt_free_bulk lib/maple_tree.c:169 [inline]
mas_destroy+0x3e0/0x650 lib/maple_tree.c:5771
mas_store_prealloc+0xf0/0x150 lib/maple_tree.c:5702
vma_iter_store mm/internal.h:1013 [inline]
vma_complete+0xad9/0x1170 mm/mmap.c:572
__split_vma+0x523/0x810 mm/mmap.c:2214
split_vma+0xc6/0x110 mm/mmap.c:2242
mbind_range+0x4d2/0x760 mm/mempolicy.c:829
__do_sys_set_mempolicy_home_node+0x323/0x480 mm/mempolicy.c:1546
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff8880782e0400
which belongs to the cache maple_node of size 256
The buggy address is located 64 bytes inside of
freed 256-byte region [ffff8880782e0400, ffff8880782e0500)

The buggy address belongs to the physical page:
page:ffffea0001e0b800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x782e0
head:ffffea0001e0b800 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffff8880124cd000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5335, tgid 5329 (syz-executor.3), ts 114724293643, free_ts 114618496841
prep_new_page mm/page_alloc.c:2553 [inline]
get_page_from_freelist+0x1190/0x2e20 mm/page_alloc.c:4326
__alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:5592
alloc_pages+0x1aa/0x270 mm/mempolicy.c:2283
alloc_slab_page mm/slub.c:1851 [inline]
allocate_slab+0x25f/0x390 mm/slub.c:1998
new_slab mm/slub.c:2051 [inline]
___slab_alloc+0xa91/0x1400 mm/slub.c:3193
__kmem_cache_alloc_bulk mm/slub.c:3952 [inline]
kmem_cache_alloc_bulk+0x270/0x860 mm/slub.c:4027
mt_alloc_bulk lib/maple_tree.c:164 [inline]
mas_alloc_nodes+0x276/0x8a0 lib/maple_tree.c:1263
mas_node_count_gfp lib/maple_tree.c:1318 [inline]
mas_preallocate+0x1bb/0x360 lib/maple_tree.c:5717
vma_iter_prealloc mm/internal.h:972 [inline]
__split_vma+0x1b7/0x810 mm/mmap.c:2177
do_vmi_align_munmap+0x34a/0xf60 mm/mmap.c:2320
do_vmi_munmap+0x26e/0x2c0 mm/mmap.c:2452
mmap_region+0x1ee/0x2620 mm/mmap.c:2500
do_mmap+0x831/0xf60 mm/mmap.c:1364
vm_mmap_pgoff+0x1af/0x280 mm/util.c:542
ksys_mmap_pgoff+0x41f/0x5a0 mm/mmap.c:1410
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1454 [inline]
free_pcp_prepare+0x5d5/0xa50 mm/page_alloc.c:1504
free_unref_page_prepare mm/page_alloc.c:3388 [inline]
free_unref_page+0x1d/0x490 mm/page_alloc.c:3483
qlink_free mm/kasan/quarantine.c:168 [inline]
qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187
kasan_quarantine_reduce+0x192/0x220 mm/kasan/quarantine.c:294
__kasan_slab_alloc+0x63/0x90 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:186 [inline]
slab_post_alloc_hook mm/slab.h:769 [inline]
slab_alloc_node mm/slub.c:3452 [inline]
slab_alloc mm/slub.c:3460 [inline]
__kmem_cache_alloc_lru mm/slub.c:3467 [inline]
kmem_cache_alloc+0x17c/0x3b0 mm/slub.c:3476
__mpol_dup+0x76/0x390 mm/mempolicy.c:2407
mpol_dup include/linux/mempolicy.h:88 [inline]
vma_replace_policy mm/mempolicy.c:773 [inline]
mbind_range+0x132/0x760 mm/mempolicy.c:839
__do_sys_set_mempolicy_home_node+0x323/0x480 mm/mempolicy.c:1546
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
ffff8880782e0300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880782e0380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880782e0400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880782e0480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880782e0500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Next message: Maxime Chevallier: "Re: [PATCH] regmap: allow upshifting register addresses before performing operations"
Previous message: Jonathan Cameron: "Re: [PATCH v5 1/6] iio: addac: stx104: Fix race condition for stx104_write_raw()"
In reply to: syzbot: "[syzbot] [mm?] KASAN: slab-use-after-free Read in mas_next_entry"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]