[PATCH] fix faulty inode data collection for open() with O_CREAT

When the specified path is an existing file or when it is a symlink, audit collects the wrong inode number, which causes it to miss the open() event. Adding a second hook to the open() path fixes this. Also add audit_copy_inode() to consolidate some code. Signed-off-by: Amy Griffis <amy.griffis(a)hp.com&gt; --- fs/namei.c | 2 ++ include/linux/audit.h | 7 +++++ kernel/auditsc.c | 63 ++++++++++++++++++++++++++++++++----------------- 3 files changed, 50 insertions(+), 22 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 184fe4a..8904b4f 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1659,6 +1659,7 @@ do_last: * It already exists. */ mutex_unlock(&dir->d_inode->i_mutex); + audit_inode_update(path.dentry->d_inode); error = -EEXIST; if (flag & O_EXCL) @@ -1669,6 +1670,7 @@ do_last: if (flag & O_NOFOLLOW) goto exit_dput; } + error = -ENOENT; if (!path.dentry->d_inode) goto exit_dput; diff --git a/include/linux/audit.h b/include/linux/audit.h index 9fcafaf..c63f204 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -328,6 +328,7 @@ extern void audit_putname(const char *na extern void __audit_inode(const char *name, const struct inode *inode); extern void __audit_inode_child(const char *dname, const struct inode *inode, unsigned long pino); +extern void __audit_inode_update(const struct inode *inode); static inline void audit_getname(const char *name) { if (unlikely(current->audit_context)) @@ -343,6 +344,10 @@ static inline void audit_inode_child(con if (unlikely(current->audit_context)) __audit_inode_child(dname, inode, pino); } +static inline void audit_inode_update(const struct inode *inode) { + if (unlikely(current->audit_context)) + __audit_inode_update(inode); +} /* Private API (for audit.c only) */ extern unsigned int audit_serial(void); @@ -414,8 +419,10 @@ #define audit_getname(n) do { ; } while #define audit_putname(n) do { ; } while (0) #define __audit_inode(n,i) do { ; } while (0) #define __audit_inode_child(d,i,p) do { ; } while (0) +#define __audit_inode_update(i) do { ; } while (0) #define audit_inode(n,i) do { ; } while (0) #define audit_inode_child(d,i,p) do { ; } while (0) +#define audit_inode_update(i) do { ; } while (0) #define auditsc_get_stamp(c,t,s) do { BUG(); } while (0) #define audit_get_loginuid(c) ({ -1; }) #define audit_ipc_obj(i) ({ 0; }) diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 53d2d74..0bc584d 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1200,14 +1200,18 @@ #if AUDIT_DEBUG #endif } -static void audit_inode_context(int idx, const struct inode *inode) +/* Copy inode data into an audit_names. */ +static void audit_copy_inode(struct audit_names *name, const struct inode *inode) { - struct audit_context *context = current->audit_context; - - selinux_get_inode_sid(inode, &context->names[idx].osid); + name->ino = inode->i_ino; + name->dev = inode->i_sb->s_dev; + name->mode = inode->i_mode; + name->uid = inode->i_uid; + name->gid = inode->i_gid; + name->rdev = inode->i_rdev; + selinux_get_inode_sid(inode, &name->osid); } - /** * audit_inode - store the inode and device from a lookup * @name: name being audited @@ -1241,13 +1245,7 @@ #if AUDIT_DEBUG ++context->ino_count; #endif } - context->names[idx].ino = inode->i_ino; - context->names[idx].dev = inode->i_sb->s_dev; - context->names[idx].mode = inode->i_mode; - context->names[idx].uid = inode->i_uid; - context->names[idx].gid = inode->i_gid; - context->names[idx].rdev = inode->i_rdev; - audit_inode_context(idx, inode); + audit_copy_inode(&context->names[idx], inode); } /** @@ -1303,16 +1301,37 @@ #endif context->names[idx].name_len = AUDIT_NAME_FULL; context->names[idx].name_put = 0; /* don't call __putname() */ - if (inode) { - context->names[idx].ino = inode->i_ino; - context->names[idx].dev = inode->i_sb->s_dev; - context->names[idx].mode = inode->i_mode; - context->names[idx].uid = inode->i_uid; - context->names[idx].gid = inode->i_gid; - context->names[idx].rdev = inode->i_rdev; - audit_inode_context(idx, inode); - } else - context->names[idx].ino = (unsigned long)-1; + if (!inode) + context->names[idx].ino = (unsigned long)-1; + else + audit_copy_inode(&context->names[idx], inode); +} + +/** + * audit_inode_update - update inode info for last collected name + * @inode: inode being audited + * + * When open() is called on an existing object with the O_CREAT flag, the inode + * data audit initially collects is incorrect. This additional hook ensures + * audit has the inode data for the actual object to be opened. + */ +void __audit_inode_update(const struct inode *inode) +{ + struct audit_context *context = current->audit_context; + int idx; + + if (!context->in_syscall || !inode) + return; + + if (context->name_count == 0) { + context->name_count++; +#if AUDIT_DEBUG + context->ino_count++; +#endif + } + idx = context->name_count - 1; + + audit_copy_inode(&context->names[idx], inode); } /** -- 1.4.0