evie/android_kernel_oneplus_msm8998
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f2fs: preserve i_mode if __f2fs_set_acl() fails

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When changing a file's acl mask, __f2fs_set_acl() will first set the
group bits of i_mode to the value of the mask, and only then set the
actual extended attribute representing the new acl.

If the second part fails (due to lack of space, for example) and the
file had no acl attribute to begin with, the system will from now on
assume that the mask permission bits are actual group permission bits,
potentially granting access to the wrong users.

Prevent this by only changing the inode mode after the acl has been set.

Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Ernesto A. Fernández 2017-07-23 22:32:54 -03:00 • committed by Jaegeuk Kim
parent d143729d71
commit ada8484098
1 changed files with 3 additions and 2 deletions
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5
fs/f2fs/acl.c
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@ -210,15 +210,16 @@ static int __f2fs_set_acl(struct inode *inode, int type,
void *value = NULL; void *value = NULL;
size_t size = 0; size_t size = 0;
int error; int error;
umode_t mode = inode->i_mode;
switch (type) { switch (type) {
case ACL_TYPE_ACCESS: case ACL_TYPE_ACCESS:
name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
if (acl && !ipage) { if (acl && !ipage) {
error = posix_acl_update_mode(inode, &inode->i_mode, &acl); error = posix_acl_update_mode(inode, &mode, &acl);
if (error) if (error)
return error; return error;
set_acl_inode(inode, inode->i_mode); set_acl_inode(inode, mode);
} }
break; break;