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| author | Al Viro | 2015-05-08 02:37:40 +0200 |
|---|---|---|
| committer | Al Viro | 2015-05-11 14:13:13 +0200 |
| commit | 31956502dd2c9432523d01373a9dc0e5931cfa1c (patch) | |
| tree | 113687c758ac261f3a72c4027baf0007ab6d5647 /fs/namei.c | |
| parent | namei: make put_link() RCU-safe (diff) | |
| download | kernel-qcow2-linux-31956502dd2c9432523d01373a9dc0e5931cfa1c.tar.gz kernel-qcow2-linux-31956502dd2c9432523d01373a9dc0e5931cfa1c.tar.xz kernel-qcow2-linux-31956502dd2c9432523d01373a9dc0e5931cfa1c.zip | |
namei: make may_follow_link() safe in RCU mode
We *can't* call that audit garbage in RCU mode - it's doing a weird
mix of allocations (GFP_NOFS, immediately followed by GFP_KERNEL)
and I'm not touching that... thing again.
So if this security sclero^Whardening feature gets triggered when
we are in RCU mode, tough - we'll fail with -ECHILD and have
everything restarted in non-RCU mode. Only to hit the same test
and fail, this time with EACCES and with (oh, rapture) an audit spew
produced.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/namei.c b/fs/namei.c index 998c3c2c9488..20bf494307c9 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -794,6 +794,9 @@ static inline int may_follow_link(struct nameidata *nd) if (uid_eq(parent->i_uid, inode->i_uid)) return 0; + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + audit_log_link_denied("follow_link", &nd->stack[0].link); return -EACCES; } |