Fix rbhz 1658675 again

This patch got dropped with the latest rebase to upstream's version of
the lockdown patches.
This commit is contained in:
Jeremy Cline 2019-06-06 18:12:27 +00:00
parent ead55fdbc7
commit 228a4ee828
2 changed files with 61 additions and 0 deletions

View File

@ -2080,3 +2080,61 @@ index bb4dc78..c2e4953 100644
+#endif /* CONFIG_ALLOW_LOCKDOWN_LIFT_BY_SYSRQ */
--
2.20.1
From patchwork Wed Nov 21 12:05:10 2018
Date: Wed, 21 Nov 2018 13:05:10 +0100
From: Vasily Gorbik <gor@linux.ibm.com>
Subject: [PATCH next-lockdown 1/1] debugfs: avoid EPERM when no open file
operation defined
With "debugfs: Restrict debugfs when the kernel is locked down"
return code "r" is unconditionally set to -EPERM, which stays like that
until function return if no "open" file operation defined, effectivelly
resulting in "Operation not permitted" for all such files despite kernel
lock down status or CONFIG_LOCK_DOWN_KERNEL being enabled.
In particular this breaks 2 debugfs files on s390:
/sys/kernel/debug/s390_hypfs/diag_304
/sys/kernel/debug/s390_hypfs/diag_204
To address that set EPERM return code only when debugfs_is_locked_down
returns true.
Fixes: 3fc322605158 ("debugfs: Restrict debugfs when the kernel is locked down")
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---
fs/debugfs/file.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 51cb894c21f2..89c86faaa02a 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -167,9 +167,10 @@ static int open_proxy_open(struct inode *inode, struct file *filp)
real_fops = debugfs_real_fops(filp);
- r = -EPERM;
- if (debugfs_is_locked_down(inode, filp, real_fops))
+ if (debugfs_is_locked_down(inode, filp, real_fops)) {
+ r = -EPERM;
goto out;
+ }
real_fops = fops_get(real_fops);
if (!real_fops) {
@@ -296,9 +297,10 @@ static int full_proxy_open(struct inode *inode, struct file *filp)
return r == -EIO ? -ENOENT : r;
real_fops = debugfs_real_fops(filp);
- r = -EPERM;
- if (debugfs_is_locked_down(inode, filp, real_fops))
+ if (debugfs_is_locked_down(inode, filp, real_fops)) {
+ r = -EPERM;
goto out;
+ }
real_fops = fops_get(real_fops);
if (!real_fops) {
--
2.21.0

View File

@ -1815,6 +1815,9 @@ fi
#
#
%changelog
* Thu Jun 06 2019 Jeremy Cline <jcline@redhat.com>
- Fix incorrect permission denied with lock down off (rhbz 1658675)
* Thu Jun 06 2019 Justin M. Forbes <jforbes@fedoraproject.org> - 5.2.0-0.rc3.git2.1
- Linux v5.2-rc3-37-g156c05917e09