[PATCH] vfs: fix audit_inode call in O_CREAT case of do_last

From: Jeff Layton
Date: Fri Apr 12 2013 - 15:16:41 EST


Jiri reported a regression in auditing of open(..., O_CREAT) syscalls.
In older kernels, creating a file with open(..., O_CREAT) created
audit_name records that looked like this:

type=PATH msg=audit(1360255720.628:64): item=1 name="/abc/foo" inode=138810 dev=fd:00 mode=0100640 ouid=0 ogid=0 rdev=00:00 obj=unconfined_u:object_r:default_t:s0
type=PATH msg=audit(1360255720.628:64): item=0 name="/abc/" inode=138635 dev=fd:00 mode=040750 ouid=0 ogid=0 rdev=00:00 obj=unconfined_u:object_r:default_t:s0

...in recent kernels though, they look like this:

type=PATH msg=audit(1360255402.886:12574): item=2 name=(null) inode=264599 dev=fd:00 mode=0100640 ouid=0 ogid=0 rdev=00:00 obj=unconfined_u:object_r:default_t:s0
type=PATH msg=audit(1360255402.886:12574): item=1 name=(null) inode=264598 dev=fd:00 mode=040750 ouid=0 ogid=0 rdev=00:00 obj=unconfined_u:object_r:default_t:s0
type=PATH msg=audit(1360255402.886:12574): item=0 name="/abc/foo" inode=264598 dev=fd:00 mode=040750 ouid=0 ogid=0 rdev=00:00 obj=unconfined_u:object_r:default_t:s0

Richard bisected to determine that the problems started with commit
bfcec708, but the log messages have changed with some later
audit-related patches.

The problem is that this audit_inode call is passing in the parent of
the dentry being opened, but audit_inode is being called with the parent
flag false. This causes later audit_inode and audit_inode_child calls to
match the wrong entry in the audit_names list.

This patch simply sets the flag to properly indicate that this inode
represents the parent. With this, the audit_names entries are back to
looking like they did before.

Cc: <stable@xxxxxxxxxxxxxxx> # v3.7+
Cc: Richard Guy Briggs <rbriggs@xxxxxxxxxx>
Reported-by: Jiri Jaburek <jjaburek@xxxxxxxxxx>
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/namei.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 57ae9c8..85e40d1 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2740,7 +2740,7 @@ static int do_last(struct nameidata *nd, struct path *path,
if (error)
return error;

- audit_inode(name, dir, 0);
+ audit_inode(name, dir, LOOKUP_PARENT);
error = -EISDIR;
/* trailing slashes? */
if (nd->last.name[nd->last.len])
--
1.7.1

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