KASAN: use-after-free Read in fscache_alloc

Title	Replies (including bot)	Last reply
[PATCH 5.9 000/757] 5.9.2-rc1 review	766 (766)	2020/10/30 08:32
[PATCH 5.8 000/633] 5.8.17-rc1 review	638 (638)	2020/10/28 22:08
KASAN: use-after-free Read in fscache_alloc_cookie	1 (4)	2020/10/13 23:22

Created	Duration	User	Patch	Repo	Result
2020/10/13 20:13	13m	dhowells@redhat.com		git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git f8eb8d1c6a853f617ca9ee233bb2d230401c5bdc	report log

Created

Duration

User

Patch

Repo

Result

2020/10/13 20:13

13m

dhowells@redhat.com

git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git f8eb8d1c6a853f617ca9ee233bb2d230401c5bdc

report log

================================================================== BUG: KASAN: use-after-free in memcpy include/linux/string.h:406 [inline] BUG: KASAN: use-after-free in fscache_set_key fs/fscache/cookie.c:93 [inline] BUG: KASAN: use-after-free in fscache_alloc_cookie+0xff/0x730 fs/fscache/cookie.c:153 Read of size 10 at addr ffff8880a6c28200 by task kworker/1:6/8760 CPU: 1 PID: 8760 Comm: kworker/1:6 Not tainted 5.9.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: afs afs_manage_cell Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x198/0x1fd lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:186 [inline] check_memory_region+0x13d/0x180 mm/kasan/generic.c:192 memcpy+0x20/0x60 mm/kasan/common.c:105 memcpy include/linux/string.h:406 [inline] fscache_set_key fs/fscache/cookie.c:93 [inline] fscache_alloc_cookie+0xff/0x730 fs/fscache/cookie.c:153 __fscache_acquire_cookie+0x16c/0x610 fs/fscache/cookie.c:288 fscache_acquire_cookie include/linux/fscache.h:334 [inline] afs_activate_cell fs/afs/cell.c:609 [inline] afs_manage_cell+0x4fa/0x11c0 fs/afs/cell.c:697 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Allocated by task 10197: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 __do_kmalloc mm/slab.c:3655 [inline] __kmalloc+0x1b0/0x360 mm/slab.c:3664 kmalloc include/linux/slab.h:559 [inline] afs_alloc_cell fs/afs/cell.c:157 [inline] afs_lookup_cell+0x5e9/0x1440 fs/afs/cell.c:262 afs_parse_source fs/afs/super.c:290 [inline] afs_parse_param+0x404/0x8c0 fs/afs/super.c:326 vfs_parse_fs_param fs/fs_context.c:117 [inline] vfs_parse_fs_param+0x203/0x550 fs/fs_context.c:98 vfs_parse_fs_string+0xe6/0x150 fs/fs_context.c:161 generic_parse_monolithic+0x16f/0x1f0 fs/fs_context.c:201 do_new_mount fs/namespace.c:2871 [inline] path_mount+0x133f/0x20a0 fs/namespace.c:3192 do_mount fs/namespace.c:3205 [inline] __do_sys_mount fs/namespace.c:3413 [inline] __se_sys_mount fs/namespace.c:3390 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3390 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 16: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422 __cache_free mm/slab.c:3418 [inline] kfree+0x10e/0x2b0 mm/slab.c:3756 afs_cell_destroy+0x1b0/0x240 fs/afs/cell.c:500 rcu_do_batch kernel/rcu/tree.c:2428 [inline] rcu_core+0x5ca/0x1130 kernel/rcu/tree.c:2656 __do_softirq+0x1f8/0xb23 kernel/softirq.c:298 The buggy address belongs to the object at ffff8880a6c28200 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff8880a6c28200, ffff8880a6c28220) The buggy address belongs to the page: page:00000000c2f50dc7 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880a6c28fc1 pfn:0xa6c28 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00028969c8 ffffea00025ca748 ffff8880aa040100 raw: ffff8880a6c28fc1 ffff8880a6c28000 000000010000003f 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a6c28100: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff8880a6c28180: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff8880a6c28200: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff8880a6c28280: 00 00 00 00 fc fc fc fc 00 fc fc fc fc fc fc fc ffff8880a6c28300: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ==================================================================