From: Gautham Ananthakrishna gautham.ananthakrishna@oracle.com

stable inclusion from stable-v5.10.227 commit aac31d654a0a31cb0d2fa36ae694f4e164a52707 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYRA7 CVE: CVE-2024-49958

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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commit 5ca60b86f57a4d9648f68418a725b3a7de2816b0 upstream.

One of our customers reported a crash and a corrupted ocfs2 filesystem. The crash was due to the detection of corruption. Upon troubleshooting, the fsck -fn output showed the below corruption

[EXTENT_LIST_FREE] Extent list in owner 33080590 claims 230 as the next free chain record, but fsck believes the largest valid value is 227. Clamp the next record value? n

The stat output from the debugfs.ocfs2 showed the following corruption where the "Next Free Rec:" had overshot the "Count:" in the root metadata block.

Inode: 33080590 Mode: 0640 Generation: 2619713622 (0x9c25a856) FS Generation: 904309833 (0x35e6ac49) CRC32: 00000000 ECC: 0000 Type: Regular Attr: 0x0 Flags: Valid Dynamic Features: (0x16) HasXattr InlineXattr Refcounted Extended Attributes Block: 0 Extended Attributes Inline Size: 256 User: 0 (root) Group: 0 (root) Size: 281320357888 Links: 1 Clusters: 141738 ctime: 0x66911b56 0x316edcb8 -- Fri Jul 12 06:02:30.829349048 2024 atime: 0x66911d6b 0x7f7a28d -- Fri Jul 12 06:11:23.133669517 2024 mtime: 0x66911b56 0x12ed75d7 -- Fri Jul 12 06:02:30.317552087 2024 dtime: 0x0 -- Wed Dec 31 17:00:00 1969 Refcount Block: 2777346 Last Extblk: 2886943 Orphan Slot: 0 Sub Alloc Slot: 0 Sub Alloc Bit: 14 Tree Depth: 1 Count: 227 Next Free Rec: 230 ## Offset Clusters Block# 0 0 2310 2776351 1 2310 2139 2777375 2 4449 1221 2778399 3 5670 731 2779423 4 6401 566 2780447 ....... .... ....... ....... .... .......

The issue was in the reflink workfow while reserving space for inline xattr. The problematic function is ocfs2_reflink_xattr_inline(). By the time this function is called the reflink tree is already recreated at the destination inode from the source inode. At this point, this function reserves space for inline xattrs at the destination inode without even checking if there is space at the root metadata block. It simply reduces the l_count from 243 to 227 thereby making space of 256 bytes for inline xattr whereas the inode already has extents beyond this index (in this case up to 230), thereby causing corruption.

The fix for this is to reserve space for inline metadata at the destination inode before the reflink tree gets recreated. The customer has verified the fix.

Link: https://lkml.kernel.org/r/20240918063844.1830332-1-gautham.ananthakrishna@or... Fixes: ef962df057aa ("ocfs2: xattr: fix inlined xattr reflink") Signed-off-by: Gautham Ananthakrishna gautham.ananthakrishna@oracle.com Reviewed-by: Joseph Qi joseph.qi@linux.alibaba.com Cc: Mark Fasheh mark@fasheh.com Cc: Joel Becker jlbec@evilplan.org Cc: Junxiao Bi junxiao.bi@oracle.com Cc: Changwei Ge gechangwei@live.cn Cc: Gang He ghe@suse.com Cc: Jun Piao piaojun@huawei.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Yi Yang yiyang13@huawei.com --- fs/ocfs2/refcounttree.c | 26 ++++++++++++++++++++++++-- fs/ocfs2/xattr.c | 11 +---------- 2 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c index 3b397fa9c9e8..85d25c211c87 100644 --- a/fs/ocfs2/refcounttree.c +++ b/fs/ocfs2/refcounttree.c @@ -27,6 +27,7 @@ #include "namei.h" #include "ocfs2_trace.h" #include "file.h" +#include "symlink.h"

#include <linux/bio.h> #include <linux/blkdev.h> @@ -4184,8 +4185,9 @@ static int __ocfs2_reflink(struct dentry *old_dentry, int ret; struct inode *inode = d_inode(old_dentry); struct buffer_head *new_bh = NULL; + struct ocfs2_inode_info *oi = OCFS2_I(inode);

- if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE) { + if (oi->ip_flags & OCFS2_INODE_SYSTEM_FILE) { ret = -EINVAL; mlog_errno(ret); goto out; @@ -4211,6 +4213,26 @@ static int __ocfs2_reflink(struct dentry *old_dentry, goto out_unlock; }

+ if ((oi->ip_dyn_features & OCFS2_HAS_XATTR_FL) && + (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL)) { + /* + * Adjust extent record count to reserve space for extended attribute. + * Inline data count had been adjusted in ocfs2_duplicate_inline_data(). + */ + struct ocfs2_inode_info *new_oi = OCFS2_I(new_inode); + + if (!(new_oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) && + !(ocfs2_inode_is_fast_symlink(new_inode))) { + struct ocfs2_dinode *new_di = (struct ocfs2_dinode *)new_bh->b_data; + struct ocfs2_dinode *old_di = (struct ocfs2_dinode *)old_bh->b_data; + struct ocfs2_extent_list *el = &new_di->id2.i_list; + int inline_size = le16_to_cpu(old_di->i_xattr_inline_size); + + le16_add_cpu(&el->l_count, -(inline_size / + sizeof(struct ocfs2_extent_rec))); + } + } + ret = ocfs2_create_reflink_node(inode, old_bh, new_inode, new_bh, preserve); if (ret) { @@ -4218,7 +4240,7 @@ static int __ocfs2_reflink(struct dentry *old_dentry, goto inode_unlock; }

- if (OCFS2_I(inode)->ip_dyn_features & OCFS2_HAS_XATTR_FL) { + if (oi->ip_dyn_features & OCFS2_HAS_XATTR_FL) { ret = ocfs2_reflink_xattrs(inode, old_bh, new_inode, new_bh, preserve); diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c index 977a739d5448..00ede36aeec9 100644 --- a/fs/ocfs2/xattr.c +++ b/fs/ocfs2/xattr.c @@ -6526,16 +6526,7 @@ static int ocfs2_reflink_xattr_inline(struct ocfs2_xattr_reflink *args) }

new_oi = OCFS2_I(args->new_inode); - /* - * Adjust extent record count to reserve space for extended attribute. - * Inline data count had been adjusted in ocfs2_duplicate_inline_data(). - */ - if (!(new_oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) && - !(ocfs2_inode_is_fast_symlink(args->new_inode))) { - struct ocfs2_extent_list *el = &new_di->id2.i_list; - le16_add_cpu(&el->l_count, -(inline_size / - sizeof(struct ocfs2_extent_rec))); - } + spin_lock(&new_oi->ip_lock); new_oi->ip_dyn_features |= OCFS2_HAS_XATTR_FL | OCFS2_INLINE_XATTR_FL; new_di->i_dyn_features = cpu_to_le16(new_oi->ip_dyn_features);