All of lore.kernel.org
 help / color / mirror / Atom feed
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: ChenXiaoSong <chenxiaosong2@huawei.com>,
	Hawkins Jiawei <yin31149@gmail.com>,
	Anton Altaparmakov <anton@tuxera.com>,
	Yongqiang Liu <liuyongqiang13@huawei.com>,
	Zhang Yi <yi.zhang@huawei.com>,
	Zhang Xiaoxu <zhangxiaoxu5@huawei.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Sasha Levin <sashal@kernel.org>,
	linux-ntfs-dev@lists.sourceforge.net
Subject: [PATCH AUTOSEL 5.10 1/7] ntfs: fix use-after-free in ntfs_ucsncmp()
Date: Mon,  1 Aug 2022 15:02:55 -0400	[thread overview]
Message-ID: <20220801190301.3819065-1-sashal@kernel.org> (raw)

From: ChenXiaoSong <chenxiaosong2@huawei.com>

[ Upstream commit 38c9c22a85aeed28d0831f230136e9cf6fa2ed44 ]

Syzkaller reported use-after-free bug as follows:

==================================================================
BUG: KASAN: use-after-free in ntfs_ucsncmp+0x123/0x130
Read of size 2 at addr ffff8880751acee8 by task a.out/879

CPU: 7 PID: 879 Comm: a.out Not tainted 5.19.0-rc4-next-20220630-00001-gcc5218c8bd2c-dirty #7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x1c0/0x2b0
 print_address_description.constprop.0.cold+0xd4/0x484
 print_report.cold+0x55/0x232
 kasan_report+0xbf/0xf0
 ntfs_ucsncmp+0x123/0x130
 ntfs_are_names_equal.cold+0x2b/0x41
 ntfs_attr_find+0x43b/0xb90
 ntfs_attr_lookup+0x16d/0x1e0
 ntfs_read_locked_attr_inode+0x4aa/0x2360
 ntfs_attr_iget+0x1af/0x220
 ntfs_read_locked_inode+0x246c/0x5120
 ntfs_iget+0x132/0x180
 load_system_files+0x1cc6/0x3480
 ntfs_fill_super+0xa66/0x1cf0
 mount_bdev+0x38d/0x460
 legacy_get_tree+0x10d/0x220
 vfs_get_tree+0x93/0x300
 do_new_mount+0x2da/0x6d0
 path_mount+0x496/0x19d0
 __x64_sys_mount+0x284/0x300
 do_syscall_64+0x3b/0xc0
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f3f2118d9ea
Code: 48 8b 0d a9 f4 0b 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 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 76 f4 0b 00 f7 d8 64 89 01 48
RSP: 002b:00007ffc269deac8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3f2118d9ea
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffc269dec00
RBP: 00007ffc269dec80 R08: 00007ffc269deb00 R09: 00007ffc269dec44
R10: 0000000000000000 R11: 0000000000000202 R12: 000055f81ab1d220
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

The buggy address belongs to the physical page:
page:0000000085430378 refcount:1 mapcount:1 mapping:0000000000000000 index:0x555c6a81d pfn:0x751ac
memcg:ffff888101f7e180
anon flags: 0xfffffc00a0014(uptodate|lru|mappedtodisk|swapbacked|node=0|zone=1|lastcpupid=0x1fffff)
raw: 000fffffc00a0014 ffffea0001bf2988 ffffea0001de2448 ffff88801712e201
raw: 0000000555c6a81d 0000000000000000 0000000100000000 ffff888101f7e180
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880751acd80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880751ace00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880751ace80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                          ^
 ffff8880751acf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880751acf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

The reason is that struct ATTR_RECORD->name_offset is 6485, end address of
name string is out of bounds.

Fix this by adding sanity check on end address of attribute name string.

[akpm@linux-foundation.org: coding-style cleanups]
[chenxiaosong2@huawei.com: cleanup suggested by Hawkins Jiawei]
  Link: https://lkml.kernel.org/r/20220709064511.3304299-1-chenxiaosong2@huawei.com
Link: https://lkml.kernel.org/r/20220707105329.4020708-1-chenxiaosong2@huawei.com
Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
Cc: Anton Altaparmakov <anton@tuxera.com>
Cc: ChenXiaoSong <chenxiaosong2@huawei.com>
Cc: Yongqiang Liu <liuyongqiang13@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Cc: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ntfs/attrib.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
index d563abc3e136..914e99173130 100644
--- a/fs/ntfs/attrib.c
+++ b/fs/ntfs/attrib.c
@@ -592,8 +592,12 @@ static int ntfs_attr_find(const ATTR_TYPE type, const ntfschar *name,
 		a = (ATTR_RECORD*)((u8*)ctx->attr +
 				le32_to_cpu(ctx->attr->length));
 	for (;;	a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length))) {
-		if ((u8*)a < (u8*)ctx->mrec || (u8*)a > (u8*)ctx->mrec +
-				le32_to_cpu(ctx->mrec->bytes_allocated))
+		u8 *mrec_end = (u8 *)ctx->mrec +
+		               le32_to_cpu(ctx->mrec->bytes_allocated);
+		u8 *name_end = (u8 *)a + le16_to_cpu(a->name_offset) +
+			       a->name_length * sizeof(ntfschar);
+		if ((u8*)a < (u8*)ctx->mrec || (u8*)a > mrec_end ||
+		    name_end > mrec_end)
 			break;
 		ctx->attr = a;
 		if (unlikely(le32_to_cpu(a->type) > le32_to_cpu(type) ||
-- 
2.35.1


             reply	other threads:[~2022-08-01 19:04 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-01 19:02 Sasha Levin [this message]
2022-08-01 19:02 ` [PATCH AUTOSEL 5.10 2/7] powerpc/64s: Disable stack variable initialisation for prom_init Sasha Levin
2022-08-01 19:02   ` Sasha Levin
2022-08-01 19:02 ` [PATCH AUTOSEL 5.10 3/7] spi: spi-rspi: Fix PIO fallback on RZ platforms Sasha Levin
2022-08-01 19:02 ` [PATCH AUTOSEL 5.10 4/7] mmu_gather: Let there be one tlb_{start,end}_vma() implementation Sasha Levin
2022-08-01 19:02 ` [PATCH AUTOSEL 5.10 5/7] mmu_gather: Force tlb-flush VM_PFNMAP vmas Sasha Levin
2022-08-01 19:03 ` [PATCH AUTOSEL 5.10 6/7] netfilter: nf_tables: add rescheduling points during loop detection walks Sasha Levin
2022-08-01 19:03 ` [PATCH AUTOSEL 5.10 7/7] ARM: findbit: fix overflowing offset Sasha Levin
2022-08-01 19:03   ` Sasha Levin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220801190301.3819065-1-sashal@kernel.org \
    --to=sashal@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=anton@tuxera.com \
    --cc=chenxiaosong2@huawei.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-ntfs-dev@lists.sourceforge.net \
    --cc=liuyongqiang13@huawei.com \
    --cc=stable@vger.kernel.org \
    --cc=yi.zhang@huawei.com \
    --cc=yin31149@gmail.com \
    --cc=zhangxiaoxu5@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.