From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Yoon Jungyeon <jungyeon@gatech.edu>,
Nikolay Borisov <nborisov@suse.com>, Qu Wenruo <wqu@suse.com>,
David Sterba <dsterba@suse.com>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 09/56] btrfs: inode: Verify inode mode to avoid NULL pointer dereference
Date: Mon, 3 Aug 2020 14:19:24 +0200 [thread overview]
Message-ID: <20200803121850.766021165@linuxfoundation.org> (raw)
In-Reply-To: <20200803121850.306734207@linuxfoundation.org>
From: Qu Wenruo <wqu@suse.com>
[ Upstream commit 6bf9e4bd6a277840d3fe8c5d5d530a1fbd3db592 ]
[BUG]
When accessing a file on a crafted image, btrfs can crash in block layer:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
PGD 136501067 P4D 136501067 PUD 124519067 PMD 0
CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.0.0-rc8-default #252
RIP: 0010:end_bio_extent_readpage+0x144/0x700
Call Trace:
<IRQ>
blk_update_request+0x8f/0x350
blk_mq_end_request+0x1a/0x120
blk_done_softirq+0x99/0xc0
__do_softirq+0xc7/0x467
irq_exit+0xd1/0xe0
call_function_single_interrupt+0xf/0x20
</IRQ>
RIP: 0010:default_idle+0x1e/0x170
[CAUSE]
The crafted image has a tricky corruption, the INODE_ITEM has a
different type against its parent dir:
item 20 key (268 INODE_ITEM 0) itemoff 2808 itemsize 160
generation 13 transid 13 size 1048576 nbytes 1048576
block group 0 mode 121644 links 1 uid 0 gid 0 rdev 0
sequence 9 flags 0x0(none)
This mode number 0120000 means it's a symlink.
But the dir item think it's still a regular file:
item 8 key (264 DIR_INDEX 5) itemoff 3707 itemsize 32
location key (268 INODE_ITEM 0) type FILE
transid 13 data_len 0 name_len 2
name: f4
item 40 key (264 DIR_ITEM 51821248) itemoff 1573 itemsize 32
location key (268 INODE_ITEM 0) type FILE
transid 13 data_len 0 name_len 2
name: f4
For symlink, we don't set BTRFS_I(inode)->io_tree.ops and leave it
empty, as symlink is only designed to have inlined extent, all handled
by tree block read. Thus no need to trigger btrfs_submit_bio_hook() for
inline file extent.
However end_bio_extent_readpage() expects tree->ops populated, as it's
reading regular data extent. This causes NULL pointer dereference.
[FIX]
This patch fixes the problem in two ways:
- Verify inode mode against its dir item when looking up inode
So in btrfs_lookup_dentry() if we find inode mode mismatch with dir
item, we error out so that corrupted inode will not be accessed.
- Verify inode mode when getting extent mapping
Only regular file should have regular or preallocated extent.
If we found regular/preallocated file extent for symlink or
the rest, we error out before submitting the read bio.
With this fix that crafted image can be rejected gracefully:
BTRFS critical (device loop0): inode mode mismatch with dir: inode mode=0121644 btrfs type=7 dir type=1
Reported-by: Yoon Jungyeon <jungyeon@gatech.edu>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202763
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/btrfs/inode.c | 41 +++++++++++++++++++++++++++++-------
fs/btrfs/tests/inode-tests.c | 1 +
2 files changed, 34 insertions(+), 8 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8dd2702ce859e..7befb7c12bd32 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5553,12 +5553,14 @@ no_delete:
}
/*
- * this returns the key found in the dir entry in the location pointer.
+ * Return the key found in the dir entry in the location pointer, fill @type
+ * with BTRFS_FT_*, and return 0.
+ *
* If no dir entries were found, returns -ENOENT.
* If found a corrupted location in dir entry, returns -EUCLEAN.
*/
static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
- struct btrfs_key *location)
+ struct btrfs_key *location, u8 *type)
{
const char *name = dentry->d_name.name;
int namelen = dentry->d_name.len;
@@ -5591,6 +5593,8 @@ static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
__func__, name, btrfs_ino(BTRFS_I(dir)),
location->objectid, location->type, location->offset);
}
+ if (!ret)
+ *type = btrfs_dir_type(path->nodes[0], di);
out:
btrfs_free_path(path);
return ret;
@@ -5826,6 +5830,11 @@ static struct inode *new_simple_dir(struct super_block *s,
return inode;
}
+static inline u8 btrfs_inode_type(struct inode *inode)
+{
+ return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
+}
+
struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
@@ -5833,18 +5842,31 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *sub_root = root;
struct btrfs_key location;
+ u8 di_type = 0;
int index;
int ret = 0;
if (dentry->d_name.len > BTRFS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
- ret = btrfs_inode_by_name(dir, dentry, &location);
+ ret = btrfs_inode_by_name(dir, dentry, &location, &di_type);
if (ret < 0)
return ERR_PTR(ret);
if (location.type == BTRFS_INODE_ITEM_KEY) {
inode = btrfs_iget(dir->i_sb, &location, root, NULL);
+ if (IS_ERR(inode))
+ return inode;
+
+ /* Do extra check against inode mode with di_type */
+ if (btrfs_inode_type(inode) != di_type) {
+ btrfs_crit(fs_info,
+"inode mode mismatch with dir: inode mode=0%o btrfs type=%u dir type=%u",
+ inode->i_mode, btrfs_inode_type(inode),
+ di_type);
+ iput(inode);
+ return ERR_PTR(-EUCLEAN);
+ }
return inode;
}
@@ -6455,11 +6477,6 @@ fail:
return ERR_PTR(ret);
}
-static inline u8 btrfs_inode_type(struct inode *inode)
-{
- return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
-}
-
/*
* utility function to add 'inode' into 'parent_inode' with
* a give name and a given sequence number.
@@ -6993,6 +7010,14 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
extent_start = found_key.offset;
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ /* Only regular file could have regular/prealloc extent */
+ if (!S_ISREG(inode->vfs_inode.i_mode)) {
+ ret = -EUCLEAN;
+ btrfs_crit(fs_info,
+ "regular/prealloc extent found for non-regular inode %llu",
+ btrfs_ino(inode));
+ goto out;
+ }
extent_end = extent_start +
btrfs_file_extent_num_bytes(leaf, item);
diff --git a/fs/btrfs/tests/inode-tests.c b/fs/btrfs/tests/inode-tests.c
index 64043f0288206..648633aae968c 100644
--- a/fs/btrfs/tests/inode-tests.c
+++ b/fs/btrfs/tests/inode-tests.c
@@ -232,6 +232,7 @@ static noinline int test_btrfs_get_extent(u32 sectorsize, u32 nodesize)
return ret;
}
+ inode->i_mode = S_IFREG;
BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
BTRFS_I(inode)->location.objectid = BTRFS_FIRST_FREE_OBJECTID;
BTRFS_I(inode)->location.offset = 0;
--
2.25.1
next prev parent reply other threads:[~2020-08-03 12:42 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-03 12:19 [PATCH 4.19 00/56] 4.19.137-rc1 review Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 01/56] crypto: ccp - Release all allocated memory if sha type is invalid Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 02/56] media: rc: prevent memory leak in cx23888_ir_probe Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 03/56] iio: imu: adis16400: fix memory leak Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 04/56] drm/amdgpu: fix multiple memory leaks in acp_hw_init Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 05/56] tracing: Have error path in predicate_parse() free its allocated memory Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 06/56] ath9k_htc: release allocated buffer if timed out Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 07/56] ath9k: " Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 08/56] drm/amd/display: prevent memory leak Greg Kroah-Hartman
2020-08-03 12:19 ` Greg Kroah-Hartman [this message]
2020-08-04 7:11 ` [PATCH 4.19 09/56] btrfs: inode: Verify inode mode to avoid NULL pointer dereference Pavel Machek
2020-08-04 7:18 ` Greg Kroah-Hartman
2020-08-10 18:05 ` David Sterba
2020-08-03 12:19 ` [PATCH 4.19 10/56] sctp: implement memory accounting on tx path Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 11/56] Btrfs: fix selftests failure due to uninitialized i_mode in test inodes Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 12/56] PCI/ASPM: Disable ASPM on ASMedia ASM1083/1085 PCIe-to-PCI bridge Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 13/56] 9p/trans_fd: Fix concurrency del of req_list in p9_fd_cancelled/p9_read_work Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 14/56] wireless: Use offsetof instead of custom macro Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 15/56] ARM: 8986/1: hw_breakpoint: Dont invoke overflow handler on uaccess watchpoints Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 16/56] random32: update the net random state on interrupt and activity Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 17/56] ARM: percpu.h: fix build error Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 18/56] Revert "drm/amdgpu: Fix NULL dereference in dpm sysfs handlers" Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 19/56] drm/amdgpu: Prevent kernel-infoleak in amdgpu_info_ioctl() Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 20/56] drm: hold gem reference until object is no longer accessed Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 21/56] random: fix circular include dependency on arm64 after addition of percpu.h Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 22/56] random32: remove net_rand_state from the latent entropy gcc plugin Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 23/56] rds: Prevent kernel-infoleak in rds_notify_queue_get() Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 24/56] xfs: fix missed wakeup on l_flush_wait Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 25/56] net/x25: Fix x25_neigh refcnt leak when x25 disconnect Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 26/56] net/x25: Fix null-ptr-deref in x25_disconnect Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 27/56] xfrm: Fix crash when the hold queue is used Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 28/56] selftests/net: rxtimestamp: fix clang issues for target arch PowerPC Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 29/56] selftests/net: psock_fanout: " Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 30/56] sh: Fix validation of system call number Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 31/56] net/mlx5: Verify Hardware supports requested ptp function on a given pin Greg Kroah-Hartman
2020-08-04 7:39 ` Pavel Machek
2020-08-03 12:19 ` [PATCH 4.19 32/56] net: lan78xx: add missing endpoint sanity check Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 33/56] net: lan78xx: fix transfer-buffer memory leak Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 34/56] mlx4: disable device on shutdown Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 35/56] mlxsw: core: Increase scope of RCU read-side critical section Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 36/56] mlxsw: core: Free EMAD transactions using kfree_rcu() Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 37/56] ibmvnic: Fix IRQ mapping disposal in error path Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 38/56] bpf: Fix map leak in HASH_OF_MAPS map Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 39/56] mac80211: mesh: Free ie data when leaving mesh Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 40/56] mac80211: mesh: Free pending skb when destroying a mpath Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 41/56] arm64/alternatives: move length validation inside the subsection Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 42/56] arm64: csum: Fix handling of bad packets Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 43/56] Bluetooth: fix kernel oops in store_pending_adv_report Greg Kroah-Hartman
2020-08-03 12:19 ` [PATCH 4.19 44/56] net: gemini: Fix missing clk_disable_unprepare() in error path of gemini_ethernet_port_probe() Greg Kroah-Hartman
2020-08-03 12:20 ` [PATCH 4.19 45/56] net/mlx5e: fix bpf_prog reference count leaks in mlx5e_alloc_rq Greg Kroah-Hartman
2020-08-03 12:20 ` [PATCH 4.19 46/56] usb: hso: Fix debug compile warning on sparc32 Greg Kroah-Hartman
2020-08-03 12:20 ` [PATCH 4.19 47/56] qed: Disable "MFW indication via attention" SPAM every 5 minutes Greg Kroah-Hartman
2020-08-03 12:20 ` [PATCH 4.19 48/56] nfc: s3fwrn5: add missing release on skb in s3fwrn5_recv_frame Greg Kroah-Hartman
2020-08-03 12:20 ` [PATCH 4.19 49/56] parisc: add support for cmpxchg on u8 pointers Greg Kroah-Hartman
2020-08-03 12:20 ` [PATCH 4.19 50/56] net: ethernet: ravb: exit if re-initialization fails in tx timeout Greg Kroah-Hartman
2020-08-03 12:20 ` [PATCH 4.19 51/56] Revert "i2c: cadence: Fix the hold bit setting" Greg Kroah-Hartman
2020-08-03 12:20 ` [PATCH 4.19 52/56] x86/unwind/orc: Fix ORC for newly forked tasks Greg Kroah-Hartman
2020-08-03 12:20 ` [PATCH 4.19 53/56] cxgb4: add missing release on skb in uld_send() Greg Kroah-Hartman
2020-08-03 12:20 ` [PATCH 4.19 54/56] xen-netfront: fix potential deadlock in xennet_remove() Greg Kroah-Hartman
2020-08-03 12:20 ` [PATCH 4.19 55/56] KVM: LAPIC: Prevent setting the tscdeadline timer if the lapic is hw disabled Greg Kroah-Hartman
2020-08-03 12:20 ` [PATCH 4.19 56/56] x86/i8259: Use printk_deferred() to prevent deadlock Greg Kroah-Hartman
2020-08-04 7:46 ` [PATCH 4.19 00/56] 4.19.137-rc1 review Pavel Machek
2020-08-04 14:53 ` Chris Paterson
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=20200803121850.766021165@linuxfoundation.org \
--to=gregkh@linuxfoundation.org \
--cc=dsterba@suse.com \
--cc=jungyeon@gatech.edu \
--cc=linux-kernel@vger.kernel.org \
--cc=nborisov@suse.com \
--cc=sashal@kernel.org \
--cc=stable@vger.kernel.org \
--cc=wqu@suse.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).