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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-06-15 19:04:55 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-06-15 19:04:55 +0300 |
commit | 979086f5e0066b4eff66e1eee123da228489985c (patch) | |
tree | 2b45e42b1122548a03273ab79dc91fd2a26a41e1 | |
parent | 018ab4fabddd94f1c96f3b59e180691b9e88d5d8 (diff) | |
parent | 168f912893407a5acb798a4a58613b5f1f98c717 (diff) | |
download | linux-979086f5e0066b4eff66e1eee123da228489985c.tar.xz |
Merge tag 'fs.fixes.v5.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull vfs idmapping fix from Christian Brauner:
"This fixes an issue where we fail to change the group of a file when
the caller owns the file and is a member of the group to change to.
This is only relevant on idmapped mounts.
There's a detailed description in the commit message and regression
tests have been added to xfstests"
* tag 'fs.fixes.v5.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
fs: account for group membership
-rw-r--r-- | fs/attr.c | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/fs/attr.c b/fs/attr.c index 66899b6e9bd8..dbe996b0dedf 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -61,9 +61,15 @@ static bool chgrp_ok(struct user_namespace *mnt_userns, const struct inode *inode, kgid_t gid) { kgid_t kgid = i_gid_into_mnt(mnt_userns, inode); - if (uid_eq(current_fsuid(), i_uid_into_mnt(mnt_userns, inode)) && - (in_group_p(gid) || gid_eq(gid, inode->i_gid))) - return true; + if (uid_eq(current_fsuid(), i_uid_into_mnt(mnt_userns, inode))) { + kgid_t mapped_gid; + + if (gid_eq(gid, inode->i_gid)) + return true; + mapped_gid = mapped_kgid_fs(mnt_userns, i_user_ns(inode), gid); + if (in_group_p(mapped_gid)) + return true; + } if (capable_wrt_inode_uidgid(mnt_userns, inode, CAP_CHOWN)) return true; if (gid_eq(kgid, INVALID_GID) && @@ -123,12 +129,20 @@ int setattr_prepare(struct user_namespace *mnt_userns, struct dentry *dentry, /* Make sure a caller can chmod. */ if (ia_valid & ATTR_MODE) { + kgid_t mapped_gid; + if (!inode_owner_or_capable(mnt_userns, inode)) return -EPERM; + + if (ia_valid & ATTR_GID) + mapped_gid = mapped_kgid_fs(mnt_userns, + i_user_ns(inode), attr->ia_gid); + else + mapped_gid = i_gid_into_mnt(mnt_userns, inode); + /* Also check the setgid bit! */ - if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid : - i_gid_into_mnt(mnt_userns, inode)) && - !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID)) + if (!in_group_p(mapped_gid) && + !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID)) attr->ia_mode &= ~S_ISGID; } |