| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 12/42] tmpfs: clear S_ISGID when setting posix ACLs | Date | Tue, 24 Jan 2017 08:55:22 +0100 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Gu Zheng <guzheng1@huawei.com>
commit 497de07d89c1410d76a15bec2bb41f24a2a89f31 upstream.
This change was missed the tmpfs modification in In CVE-2016-7097 commit 073931017b49 ("posix_acl: Clear SGID bit when setting file permissions") It can test by xfstest generic/375, which failed to clear setgid bit in the following test case on tmpfs:
touch $testfile chown 100:100 $testfile chmod 2755 $testfile _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile
Signed-off-by: Gu Zheng <guzheng1@huawei.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Brad Spengler <spender@grsecurity.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/posix_acl.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
--- a/fs/posix_acl.c +++ b/fs/posix_acl.c @@ -903,11 +903,10 @@ int simple_set_acl(struct inode *inode, int error; if (type == ACL_TYPE_ACCESS) { - error = posix_acl_equiv_mode(acl, &inode->i_mode); - if (error < 0) - return 0; - if (error == 0) - acl = NULL; + error = posix_acl_update_mode(inode, + &inode->i_mode, &acl); + if (error) + return error; } inode->i_ctime = CURRENT_TIME;
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