linux/fs/f2fs
Chao Yu 4dbe38dc38 f2fs: fix to do sanity check with reserved blkaddr of inline inode
As Wen Xu reported in bugzilla, after image was injected with random data
by fuzzing, inline inode would contain invalid reserved blkaddr, then
during inline conversion, we will encounter illegal memory accessing
reported by KASAN, the root cause of this is when writing out converted
inline page, we will use invalid reserved blkaddr to update sit bitmap,
result in accessing memory beyond sit bitmap boundary.

In order to fix this issue, let's do sanity check with reserved block
address of inline inode to avoid above condition.

https://bugzilla.kernel.org/show_bug.cgi?id=200179

[ 1428.846352] BUG: KASAN: use-after-free in update_sit_entry+0x80/0x7f0
[ 1428.846618] Read of size 4 at addr ffff880194483540 by task a.out/2741

[ 1428.846855] CPU: 0 PID: 2741 Comm: a.out Tainted: G        W         4.17.0+ #1
[ 1428.846858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[ 1428.846860] Call Trace:
[ 1428.846868]  dump_stack+0x71/0xab
[ 1428.846875]  print_address_description+0x6b/0x290
[ 1428.846881]  kasan_report+0x28e/0x390
[ 1428.846888]  ? update_sit_entry+0x80/0x7f0
[ 1428.846898]  update_sit_entry+0x80/0x7f0
[ 1428.846906]  f2fs_allocate_data_block+0x6db/0xc70
[ 1428.846914]  ? f2fs_get_node_info+0x14f/0x590
[ 1428.846920]  do_write_page+0xc8/0x150
[ 1428.846928]  f2fs_outplace_write_data+0xfe/0x210
[ 1428.846935]  ? f2fs_do_write_node_page+0x170/0x170
[ 1428.846941]  ? radix_tree_tag_clear+0xff/0x130
[ 1428.846946]  ? __mod_node_page_state+0x22/0xa0
[ 1428.846951]  ? inc_zone_page_state+0x54/0x100
[ 1428.846956]  ? __test_set_page_writeback+0x336/0x5d0
[ 1428.846964]  f2fs_convert_inline_page+0x407/0x6d0
[ 1428.846971]  ? f2fs_read_inline_data+0x3b0/0x3b0
[ 1428.846978]  ? __get_node_page+0x335/0x6b0
[ 1428.846987]  f2fs_convert_inline_inode+0x41b/0x500
[ 1428.846994]  ? f2fs_convert_inline_page+0x6d0/0x6d0
[ 1428.847000]  ? kasan_unpoison_shadow+0x31/0x40
[ 1428.847005]  ? kasan_kmalloc+0xa6/0xd0
[ 1428.847024]  f2fs_file_mmap+0x79/0xc0
[ 1428.847029]  mmap_region+0x58b/0x880
[ 1428.847037]  ? arch_get_unmapped_area+0x370/0x370
[ 1428.847042]  do_mmap+0x55b/0x7a0
[ 1428.847048]  vm_mmap_pgoff+0x16f/0x1c0
[ 1428.847055]  ? vma_is_stack_for_current+0x50/0x50
[ 1428.847062]  ? __fsnotify_update_child_dentry_flags.part.1+0x160/0x160
[ 1428.847068]  ? do_sys_open+0x206/0x2a0
[ 1428.847073]  ? __fget+0xb4/0x100
[ 1428.847079]  ksys_mmap_pgoff+0x278/0x360
[ 1428.847085]  ? find_mergeable_anon_vma+0x50/0x50
[ 1428.847091]  do_syscall_64+0x73/0x160
[ 1428.847098]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1428.847102] RIP: 0033:0x7fb1430766ba
[ 1428.847103] Code: 89 f5 41 54 49 89 fc 55 53 74 35 49 63 e8 48 63 da 4d 89 f9 49 89 e8 4d 63 d6 48 89 da 4c 89 ee 4c 89 e7 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 56 5b 5d 41 5c 41 5d 41 5e 41 5f c3 0f 1f 00
[ 1428.847162] RSP: 002b:00007ffc651d9388 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
[ 1428.847167] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fb1430766ba
[ 1428.847170] RDX: 0000000000000001 RSI: 0000000000001000 RDI: 0000000000000000
[ 1428.847173] RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000000
[ 1428.847176] R10: 0000000000008002 R11: 0000000000000246 R12: 0000000000000000
[ 1428.847179] R13: 0000000000001000 R14: 0000000000008002 R15: 0000000000000000

[ 1428.847252] Allocated by task 2683:
[ 1428.847372]  kasan_kmalloc+0xa6/0xd0
[ 1428.847380]  kmem_cache_alloc+0xc8/0x1e0
[ 1428.847385]  getname_flags+0x73/0x2b0
[ 1428.847390]  user_path_at_empty+0x1d/0x40
[ 1428.847395]  vfs_statx+0xc1/0x150
[ 1428.847401]  __do_sys_newlstat+0x7e/0xd0
[ 1428.847405]  do_syscall_64+0x73/0x160
[ 1428.847411]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

[ 1428.847466] Freed by task 2683:
[ 1428.847566]  __kasan_slab_free+0x137/0x190
[ 1428.847571]  kmem_cache_free+0x85/0x1e0
[ 1428.847575]  filename_lookup+0x191/0x280
[ 1428.847580]  vfs_statx+0xc1/0x150
[ 1428.847585]  __do_sys_newlstat+0x7e/0xd0
[ 1428.847590]  do_syscall_64+0x73/0x160
[ 1428.847596]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

[ 1428.847648] The buggy address belongs to the object at ffff880194483300
                which belongs to the cache names_cache of size 4096
[ 1428.847946] The buggy address is located 576 bytes inside of
                4096-byte region [ffff880194483300, ffff880194484300)
[ 1428.848234] The buggy address belongs to the page:
[ 1428.848366] page:ffffea0006512000 count:1 mapcount:0 mapping:ffff8801f3586380 index:0x0 compound_mapcount: 0
[ 1428.848606] flags: 0x17fff8000008100(slab|head)
[ 1428.848737] raw: 017fff8000008100 dead000000000100 dead000000000200 ffff8801f3586380
[ 1428.848931] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
[ 1428.849122] page dumped because: kasan: bad access detected

[ 1428.849305] Memory state around the buggy address:
[ 1428.849436]  ffff880194483400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 1428.849620]  ffff880194483480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 1428.849804] >ffff880194483500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 1428.849985]                                            ^
[ 1428.850120]  ffff880194483580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 1428.850303]  ffff880194483600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 1428.850498] ==================================================================

Reported-by: Wen Xu <wen.xu@gatech.edu>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2018-07-28 18:26:08 -07:00
..
acl.c posix_acl: convert posix_acl.a_refcount from atomic_t to refcount_t 2018-01-02 19:27:28 -08:00
acl.h f2fs: remove dead code f2fs_check_acl 2016-09-14 16:52:36 -07:00
checkpoint.c f2fs: introduce and spread verify_blkaddr 2018-07-27 18:03:59 +09:00
data.c f2fs: introduce and spread verify_blkaddr 2018-07-27 18:03:59 +09:00
debug.c f2fs: Allocate and stat mem used by free nid bitmap more accurately 2018-07-28 18:23:26 -07:00
dir.c f2fs: clean up symbol namespace 2018-05-31 11:31:53 -07:00
extent_cache.c f2fs: clean up symbol namespace 2018-05-31 11:31:53 -07:00
f2fs.h f2fs: disable f2fs_check_rb_tree_consistence 2018-07-27 18:03:59 +09:00
file.c f2fs: introduce and spread verify_blkaddr 2018-07-27 18:03:59 +09:00
gc.c f2fs: let sync node IO interrupt async one 2018-06-04 14:33:20 -07:00
gc.h f2fs: introduce sbi->gc_mode to determine the policy 2018-05-31 11:31:51 -07:00
hash.c f2fs: check entire encrypted bigname when finding a dentry 2017-05-04 11:44:35 -04:00
inline.c f2fs: fix to do sanity check with reserved blkaddr of inline inode 2018-07-28 18:26:08 -07:00
inode.c f2fs: fix to do sanity check with node footer and iblocks 2018-07-28 18:26:06 -07:00
Kconfig fs/*/Kconfig: drop links to 404-compliant http://acl.bestbits.at 2018-01-01 12:45:37 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
namei.c f2fs: use timespec64 for inode timestamps 2018-07-27 18:03:59 +09:00
node.c f2fs: Allocate and stat mem used by free nid bitmap more accurately 2018-07-28 18:23:26 -07:00
node.h f2fs: support in-memory inode checksum when checking consistency 2018-07-27 18:03:59 +09:00
recovery.c f2fs: introduce and spread verify_blkaddr 2018-07-27 18:03:59 +09:00
segment.c f2fs: fix to correct return value of f2fs_trim_fs 2018-07-27 18:03:59 +09:00
segment.h f2fs: introduce and spread verify_blkaddr 2018-07-27 18:03:59 +09:00
shrinker.c f2fs: clean up symbol namespace 2018-05-31 11:31:53 -07:00
super.c f2fs: fix to do sanity check with user_block_count 2018-07-28 18:23:23 -07:00
sysfs.c f2fs: avoid potential deadlock in f2fs_sbi_store 2018-07-27 18:03:59 +09:00
trace.c f2fs: fix potential hangtask in f2fs_trace_pid 2018-01-02 19:27:30 -08:00
trace.h f2fs: add sbi and page pointer in f2fs_io_info 2015-05-28 15:41:32 -07:00
xattr.c f2fs: clean up symbol namespace 2018-05-31 11:31:53 -07:00
xattr.h f2fs: guard macro variables with braces 2017-04-10 19:48:10 -07:00