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authorZhihao Cheng <chengzhihao1@huawei.com>2022-07-19 11:00:17 +0300
committerRichard Weinberger <richard@nod.at>2022-09-21 12:32:58 +0300
commita0c51565730729f0df2ee886e34b4da6d359a10b (patch)
tree4ec778055e3885616483d66f95d417c04d544d36 /fs/ubifs/dir.c
parent713346ca1db2bebd4c7c4d5ea364ed03d504f5ed (diff)
downloadlinux-a0c51565730729f0df2ee886e34b4da6d359a10b.tar.xz
ubifs: Fix AA deadlock when setting xattr for encrypted file
Following process: vfs_setxattr(host) ubifs_xattr_set down_write(host_ui->xattr_sem) <- lock first time create_xattr ubifs_new_inode(host) fscrypt_prepare_new_inode(host) fscrypt_policy_to_inherit(host) if (IS_ENCRYPTED(inode)) fscrypt_require_key(host) fscrypt_get_encryption_info(host) ubifs_xattr_get(host) down_read(host_ui->xattr_sem) <- AA deadlock , which may trigger an AA deadlock problem: [ 102.620871] INFO: task setfattr:1599 blocked for more than 10 seconds. [ 102.625298] Not tainted 5.19.0-rc7-00001-gb666b6823ce0-dirty #711 [ 102.628732] task:setfattr state:D stack: 0 pid: 1599 [ 102.628749] Call Trace: [ 102.628753] <TASK> [ 102.628776] __schedule+0x482/0x1060 [ 102.629964] schedule+0x92/0x1a0 [ 102.629976] rwsem_down_read_slowpath+0x287/0x8c0 [ 102.629996] down_read+0x84/0x170 [ 102.630585] ubifs_xattr_get+0xd1/0x370 [ubifs] [ 102.630730] ubifs_crypt_get_context+0x1f/0x30 [ubifs] [ 102.630791] fscrypt_get_encryption_info+0x7d/0x1c0 [ 102.630810] fscrypt_policy_to_inherit+0x56/0xc0 [ 102.630817] fscrypt_prepare_new_inode+0x35/0x160 [ 102.630830] ubifs_new_inode+0xcc/0x4b0 [ubifs] [ 102.630873] ubifs_xattr_set+0x591/0x9f0 [ubifs] [ 102.630961] xattr_set+0x8c/0x3e0 [ubifs] [ 102.631003] __vfs_setxattr+0x71/0xc0 [ 102.631026] vfs_setxattr+0x105/0x270 [ 102.631034] do_setxattr+0x6d/0x110 [ 102.631041] setxattr+0xa0/0xd0 [ 102.631087] __x64_sys_setxattr+0x2f/0x40 Fetch a reproducer in [Link]. Just like ext4 does, which skips encrypting for inode with EXT4_EA_INODE_FL flag. Stop encypting xattr inode for ubifs. Link: https://bugzilla.kernel.org/show_bug.cgi?id=216260 Fixes: f4e3634a3b64222 ("ubifs: Fix races between xattr_{set|get} ...") Fixes: d475a507457b5ca ("ubifs: Add skeleton for fscrypto") Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'fs/ubifs/dir.c')
-rw-r--r--fs/ubifs/dir.c25
1 files changed, 14 insertions, 11 deletions
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index 7306f88b2c7e..8d0f68f8907c 100644
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -68,13 +68,14 @@ static int inherit_flags(const struct inode *dir, umode_t mode)
* @c: UBIFS file-system description object
* @dir: parent directory inode
* @mode: inode mode flags
+ * @is_xattr: whether the inode is xattr inode
*
* This function finds an unused inode number, allocates new inode and
* initializes it. Returns new inode in case of success and an error code in
* case of failure.
*/
struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir,
- umode_t mode)
+ umode_t mode, bool is_xattr)
{
int err;
struct inode *inode;
@@ -99,10 +100,12 @@ struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir,
current_time(inode);
inode->i_mapping->nrpages = 0;
- err = fscrypt_prepare_new_inode(dir, inode, &encrypted);
- if (err) {
- ubifs_err(c, "fscrypt_prepare_new_inode failed: %i", err);
- goto out_iput;
+ if (!is_xattr) {
+ err = fscrypt_prepare_new_inode(dir, inode, &encrypted);
+ if (err) {
+ ubifs_err(c, "fscrypt_prepare_new_inode failed: %i", err);
+ goto out_iput;
+ }
}
switch (mode & S_IFMT) {
@@ -309,7 +312,7 @@ static int ubifs_create(struct user_namespace *mnt_userns, struct inode *dir,
sz_change = CALC_DENT_SIZE(fname_len(&nm));
- inode = ubifs_new_inode(c, dir, mode);
+ inode = ubifs_new_inode(c, dir, mode, false);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_fname;
@@ -370,7 +373,7 @@ static struct inode *create_whiteout(struct inode *dir, struct dentry *dentry)
if (err)
return ERR_PTR(err);
- inode = ubifs_new_inode(c, dir, mode);
+ inode = ubifs_new_inode(c, dir, mode, false);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_free;
@@ -462,7 +465,7 @@ static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
return err;
}
- inode = ubifs_new_inode(c, dir, mode);
+ inode = ubifs_new_inode(c, dir, mode, false);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_budg;
@@ -1004,7 +1007,7 @@ static int ubifs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
sz_change = CALC_DENT_SIZE(fname_len(&nm));
- inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
+ inode = ubifs_new_inode(c, dir, S_IFDIR | mode, false);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_fname;
@@ -1091,7 +1094,7 @@ static int ubifs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
sz_change = CALC_DENT_SIZE(fname_len(&nm));
- inode = ubifs_new_inode(c, dir, mode);
+ inode = ubifs_new_inode(c, dir, mode, false);
if (IS_ERR(inode)) {
kfree(dev);
err = PTR_ERR(inode);
@@ -1173,7 +1176,7 @@ static int ubifs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
sz_change = CALC_DENT_SIZE(fname_len(&nm));
- inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
+ inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO, false);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_fname;