From: Xiaolei Li xiaolei.li@mediatek.com

This is a conceptual cherry-pick of commit d8db5b1ca9d4c57e49893d0f78e6d5ce81450cc8 upstream.

The inode is not locked in init_xattrs when creating a new inode.

Without this patch, there will occurs assert when booting or creating a new file, if the kernel config CONFIG_SECURITY_SMACK is enabled.

Log likes:

UBIFS assert failed in ubifs_xattr_set at 298 (pid 1156) CPU: 1 PID: 1156 Comm: ldconfig Tainted: G S 4.12.0-rc1-207440-g1e70b02 #2 Hardware name: MediaTek MT2712 evaluation board (DT) Call trace: [<ffff000008088538>] dump_backtrace+0x0/0x238 [<ffff000008088834>] show_stack+0x14/0x20 [<ffff0000083d98d4>] dump_stack+0x9c/0xc0 [<ffff00000835d524>] ubifs_xattr_set+0x374/0x5e0 [<ffff00000835d7ec>] init_xattrs+0x5c/0xb8 [<ffff000008385788>] security_inode_init_security+0x110/0x190 [<ffff00000835e058>] ubifs_init_security+0x30/0x68 [<ffff00000833ada0>] ubifs_mkdir+0x100/0x200 [<ffff00000820669c>] vfs_mkdir+0x11c/0x1b8 [<ffff00000820b73c>] SyS_mkdirat+0x74/0xd0 [<ffff000008082f8c>] __sys_trace_return+0x0/0x4

Signed-off-by: Xiaolei Li xiaolei.li@mediatek.com Signed-off-by: Richard Weinberger richard@nod.at Cc: stable@vger.kernel.org (julia: massaged to apply to 4.9.y, which doesn't contain fscrypto support) Signed-off-by: Julia Cartwright julia@ni.com --- Hey all-

We reproduced the issue fixed upstream by Xiaolei Li's commit in 4.9.y, with the very similar backtrace:

UBIFS assert failed in __ubifs_setxattr at 282 (pid 1362) CPU: 1 PID: 1362 Comm: sed Not tainted 4.9.47-rt37 #1 Backtrace: (dump_backtrace) from (show_stack+0x20/0x24) (show_stack) from (dump_stack+0x80/0xa0) (dump_stack) from (__ubifs_setxattr+0x84/0x634) (__ubifs_setxattr) from (init_xattrs+0x70/0xac) (init_xattrs) from (security_inode_init_security+0x100/0x144) (security_inode_init_security) from (ubifs_init_security+0x38/0x6c) (ubifs_init_security) from (ubifs_create+0xe8/0x1fc) (ubifs_create) from (path_openat+0x97c/0x1090) (path_openat) from (do_filp_open+0x48/0x94) (do_filp_open) from (do_sys_open+0x134/0x1d8) (do_sys_open) from (SyS_open+0x30/0x34) (SyS_open) from (ret_fast_syscall+0x0/0x3c)

Please consider applying this to 4.9.y at the very least, it may apply further back as well.

Thanks! Julia

fs/ubifs/xattr.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c index d9f9615bfd71..3979d767a0cb 100644 --- a/fs/ubifs/xattr.c +++ b/fs/ubifs/xattr.c @@ -270,7 +270,8 @@ static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum) }

static int __ubifs_setxattr(struct inode *host, const char *name, - const void *value, size_t size, int flags) + const void *value, size_t size, int flags, + bool check_lock) { struct inode *inode; struct ubifs_info *c = host->i_sb->s_fs_info; @@ -279,7 +280,8 @@ static int __ubifs_setxattr(struct inode *host, const char *name, union ubifs_key key; int err;

- ubifs_assert(inode_is_locked(host)); + if (check_lock) + ubifs_assert(inode_is_locked(host));

if (size > UBIFS_MAX_INO_DATA) return -ERANGE; @@ -548,7 +550,8 @@ static int init_xattrs(struct inode *inode, const struct xattr *xattr_array, } strcpy(name, XATTR_SECURITY_PREFIX); strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name); - err = __ubifs_setxattr(inode, name, xattr->value, xattr->value_len, 0); + err = __ubifs_setxattr(inode, name, xattr->value, + xattr->value_len, 0, false); kfree(name); if (err < 0) break; @@ -594,7 +597,8 @@ static int ubifs_xattr_set(const struct xattr_handler *handler, name = xattr_full_name(handler, name);

if (value) - return __ubifs_setxattr(inode, name, value, size, flags); + return __ubifs_setxattr(inode, name, value, size, flags, + true); else return __ubifs_removexattr(inode, name); }