diff options
| -rw-r--r-- | fs/attr.c | 25 | ||||
| -rw-r--r-- | fs/internal.h | 5 |
2 files changed, 30 insertions, 0 deletions
diff --git a/fs/attr.c b/fs/attr.c index 666489157978..c8049ae34a2e 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -20,6 +20,31 @@ #include "internal.h" +/** + * setattr_should_drop_sgid - determine whether the setgid bit needs to be + * removed + * @inode: inode to check + * + * This function determines whether the setgid bit needs to be removed. + * We retain backwards compatibility and require setgid bit to be removed + * unconditionally if S_IXGRP is set. Otherwise we have the exact same + * requirements as setattr_prepare() and setattr_copy(). + * + * Return: ATTR_KILL_SGID if setgid bit needs to be removed, 0 otherwise. + */ +int setattr_should_drop_sgid(const struct inode *inode) +{ + umode_t mode = inode->i_mode; + + if (!(mode & S_ISGID)) + return 0; + if (mode & S_IXGRP) + return ATTR_KILL_SGID; + if (!in_group_or_capable(inode, inode->i_gid)) + return ATTR_KILL_SGID; + return 0; +} + /* * The logic we want is * diff --git a/fs/internal.h b/fs/internal.h index 0fe920d9f393..d5d9fcdae10c 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -197,3 +197,8 @@ int sb_init_dio_done_wq(struct super_block *sb); */ int do_statx(int dfd, const char __user *filename, unsigned flags, unsigned int mask, struct statx __user *buffer); + +/* + * fs/attr.c + */ +int setattr_should_drop_sgid(const struct inode *inode); |