Hi Greg, Sasha,
These two were missing in 4.4-stable. Please apply to your queue.
80e46cf22ba0 ("btrfs: tree-checker: Enhance chunk checker to validate chunk profile")
6bf9e4bd6a27 ("btrfs: inode: Verify inode mode to avoid NULL pointer dereference")
--
Regards
Sudip
>From c5d445abc052532ded78586dc62d062546f815b3 Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu@xxxxxxxx>
Date: Wed, 13 Mar 2019 12:17:50 +0800
Subject: [PATCH 1/2] btrfs: tree-checker: Enhance chunk checker to validate chunk profile
commit 80e46cf22ba0bcb57b39c7c3b52961ab3a0fd5f2 upstream
Btrfs-progs already have a comprehensive type checker, to ensure there
is only 0 (SINGLE profile) or 1 (DUP/RAID0/1/5/6/10) bit set for chunk
profile bits.
Do the same work for kernel.
Reported-by: Yoon Jungyeon <jungyeon@xxxxxxxxxx>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202765
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
[sudip: manually backport, use btrfs_err with root->fs_info]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
---
fs/btrfs/volumes.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 2d10b818399b..cd1e9411f926 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6262,6 +6262,13 @@ static int btrfs_check_chunk_valid(struct btrfs_root *root,
return -EIO;
}
+ if (!is_power_of_2(type & BTRFS_BLOCK_GROUP_PROFILE_MASK) &&
+ (type & BTRFS_BLOCK_GROUP_PROFILE_MASK) != 0) {
+ btrfs_err(root->fs_info,
+ "invalid chunk profile flag: 0x%llx, expect 0 or 1 bit set",
+ type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
+ return -EUCLEAN;
+ }
if ((type & BTRFS_BLOCK_GROUP_TYPE_MASK) == 0) {
btrfs_err(root->fs_info, "missing chunk type flag: 0x%llx", type);
return -EIO;
--
2.11.0
>From 6bdcf8c246aa2a0289e59413a61ee67ab0c6a1f8 Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu@xxxxxxxx>
Date: Wed, 13 Mar 2019 13:55:11 +0800
Subject: [PATCH 2/2] btrfs: inode: Verify inode mode to avoid NULL pointer dereference
commit 6bf9e4bd6a277840d3fe8c5d5d530a1fbd3db592 upstream
[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@xxxxxxxxxx>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202763
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
[sudip: use original btrfs_inode_type(), btrfs_crit with root->fs_info,
ISREG with inode->i_mode and adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
---
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 b1125778b908..9e1f9910bdf2 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5370,11 +5370,13 @@ 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, location->objectid is 0.
*/
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;
@@ -5396,6 +5398,8 @@ static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
goto out_err;
btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
+ if (!ret)
+ *type = btrfs_dir_type(path->nodes[0], di);
out:
btrfs_free_path(path);
return ret;
@@ -5681,19 +5685,25 @@ 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 inode *inode;
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);
@@ -5702,6 +5712,18 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
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(root->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;
}
@@ -6315,11 +6337,6 @@ 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.
@@ -6904,6 +6921,14 @@ again:
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->i_mode)) {
+ ret = -EUCLEAN;
+ btrfs_crit(root->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);
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
diff --git a/fs/btrfs/tests/inode-tests.c b/fs/btrfs/tests/inode-tests.c
index 054fc0d97131..5ff676df698f 100644
--- a/fs/btrfs/tests/inode-tests.c
+++ b/fs/btrfs/tests/inode-tests.c
@@ -235,6 +235,7 @@ static noinline int test_btrfs_get_extent(void)
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;
--
2.11.0
