[PATCH AUTOSEL 6.2 05/18] fs/ntfs3: Enhance the attribute size check

Sasha Levin
2023-05-09T21:21:37Z

From: Edward Lo <edward.lo@ambergroup.io>

[ Upstream commit 4f082a7531223a438c757bb20e304f4c941c67a8 ]

This combines the overflow and boundary check so that all attribute size
will be properly examined while enumerating them.

[ 169.181521] BUG: KASAN: slab-out-of-bounds in run_unpack+0x2e3/0x570
[ 169.183161] Read of size 1 at addr ffff8880094b6240 by task mount/247
[ 169.184046]
[ 169.184925] CPU: 0 PID: 247 Comm: mount Not tainted 6.0.0-rc7+ #3
[ 169.185908] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 169.187066] Call Trace:
[ 169.187492] <TASK>
[ 169.188049] dump_stack_lvl+0x49/0x63
[ 169.188495] print_report.cold+0xf5/0x689
[ 169.188964] ? run_unpack+0x2e3/0x570
[ 169.189331] kasan_report+0xa7/0x130
[ 169.189714] ? run_unpack+0x2e3/0x570
[ 169.190079] __asan_load1+0x51/0x60
[ 169.190634] run_unpack+0x2e3/0x570
[ 169.191290] ? run_pack+0x840/0x840
[ 169.191569] ? run_lookup_entry+0xb3/0x1f0
[ 169.192443] ? mi_enum_attr+0x20a/0x230
[ 169.192886] run_unpack_ex+0xad/0x3e0
[ 169.193276] ? run_unpack+0x570/0x570
[ 169.193557] ? ni_load_mi+0x80/0x80
[ 169.193889] ? debug_smp_processor_id+0x17/0x20
[ 169.194236] ? mi_init+0x4a/0x70
[ 169.194496] attr_load_runs_vcn+0x166/0x1c0
[ 169.194851] ? attr_data_write_resident+0x250/0x250
[ 169.195188] mi_read+0x133/0x2c0
[ 169.195481] ntfs_iget5+0x277/0x1780
[ 169.196017] ? call_rcu+0x1c7/0x330
[ 169.196392] ? ntfs_get_block_bmap+0x70/0x70
[ 169.196708] ? evict+0x223/0x280
[ 169.197014] ? __kmalloc+0x33/0x540
[ 169.197305] ? wnd_init+0x15b/0x1b0
[ 169.197599] ntfs_fill_super+0x1026/0x1ba0
[ 169.197994] ? put_ntfs+0x1d0/0x1d0
[ 169.198299] ? vsprintf+0x20/0x20
[ 169.198583] ? mutex_unlock+0x81/0xd0
[ 169.198930] ? set_blocksize+0x95/0x150
[ 169.199269] get_tree_bdev+0x232/0x370
[ 169.199750] ? put_ntfs+0x1d0/0x1d0
[ 169.200094] ntfs_fs_get_tree+0x15/0x20
[ 169.200431] vfs_get_tree+0x4c/0x130
[ 169.200714] path_mount+0x654/0xfe0
[ 169.201067] ? putname+0x80/0xa0
[ 169.201358] ? finish_automount+0x2e0/0x2e0
[ 169.201965] ? putname+0x80/0xa0
[ 169.202445] ? kmem_cache_free+0x1c4/0x440
[ 169.203075] ? putname+0x80/0xa0
[ 169.203414] do_mount+0xd6/0xf0
[ 169.203719] ? path_mount+0xfe0/0xfe0
[ 169.203977] ? __kasan_check_write+0x14/0x20
[ 169.204382] __x64_sys_mount+0xca/0x110
[ 169.204711] do_syscall_64+0x3b/0x90
[ 169.205059] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 169.205571] RIP: 0033:0x7f67a80e948a
[ 169.206327] Code: 48 8b 0d 11 fa 2a 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 008
[ 169.208296] RSP: 002b:00007ffddf020f58 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
[ 169.209253] RAX: ffffffffffffffda RBX: 000055e2547a6060 RCX: 00007f67a80e948a
[ 169.209777] RDX: 000055e2547a6260 RSI: 000055e2547a62e0 RDI: 000055e2547aeaf0
[ 169.210342] RBP: 0000000000000000 R08: 000055e2547a6280 R09: 0000000000000020
[ 169.210843] R10: 00000000c0ed0000 R11: 0000000000000202 R12: 000055e2547aeaf0
[ 169.211307] R13: 000055e2547a6260 R14: 0000000000000000 R15: 00000000ffffffff
[ 169.211913] </TASK>
[ 169.212304]
[ 169.212680] Allocated by task 0:
[ 169.212963] (stack is not available)
[ 169.213200]
[ 169.213472] The buggy address belongs to the object at ffff8880094b5e00
[ 169.213472] which belongs to the cache UDP of size 1152
[ 169.214095] The buggy address is located 1088 bytes inside of
[ 169.214095] 1152-byte region [ffff8880094b5e00, ffff8880094b6280)
[ 169.214639]
[ 169.215004] The buggy address belongs to the physical page:
[ 169.215766] page:000000002e324c8c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x94b4
[ 169.218412] head:000000002e324c8c order:2 compound_mapcount:0 compound_pincount:0
[ 169.219078] flags: 0xfffffc0010200(slab|head|node=0|zone=1|lastcpupid=0x1fffff)
[ 169.220272] raw: 000fffffc0010200 0000000000000000 dead000000000122 ffff888002409b40
[ 169.221006] raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000
[ 169.222320] page dumped because: kasan: bad access detected
[ 169.222922]
[ 169.223119] Memory state around the buggy address:
[ 169.224056] ffff8880094b6100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 169.224908] ffff8880094b6180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 169.225677] >ffff8880094b6200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 169.226445] ^
[ 169.227055] ffff8880094b6280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 169.227638] ffff8880094b6300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

Signed-off-by: Edward Lo <edward.lo@ambergroup.io>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ntfs3/record.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/fs/ntfs3/record.c b/fs/ntfs3/record.c
index defce6a5c8e1b..abfe004774c03 100644
--- a/fs/ntfs3/record.c
+++ b/fs/ntfs3/record.c
@@ -220,11 +220,6 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
return NULL;
}

- if (off + asize < off) {
- /* overflow check */
- return NULL;
- }
-
attr = Add2Ptr(attr, asize);
off += asize;
}
@@ -247,8 +242,8 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
if ((t32 & 0xf) || (t32 > 0x100))
return NULL;

- /* Check boundary. */
- if (off + asize > used)
+ /* Check overflow and boundary. */
+ if (off + asize < off || off + asize > used)
return NULL;

/* Check size of attribute. */
--
2.39.2