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| author | Stefan Berger <stefanb@linux.ibm.com> | 2024-03-22 17:03:12 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-06-21 15:40:38 +0300 |
| commit | a78a6f0da57d058e2009e9958fdcef66f165208c (patch) | |
| tree | 33f2b72e00234b03a9d27680003e879c1813296a /security/integrity/ima/ima_api.c | |
| parent | 03ea2b129344152157418929f06726989efc0445 (diff) | |
| download | linux-a78a6f0da57d058e2009e9958fdcef66f165208c.tar.xz | |
ima: Fix use-after-free on a dentry's dname.name
commit be84f32bb2c981ca670922e047cdde1488b233de upstream.
->d_name.name can change on rename and the earlier value can be freed;
there are conditions sufficient to stabilize it (->d_lock on dentry,
->d_lock on its parent, ->i_rwsem exclusive on the parent's inode,
rename_lock), but none of those are met at any of the sites. Take a stable
snapshot of the name instead.
Link: https://lore.kernel.org/all/20240202182732.GE2087318@ZenIV/
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'security/integrity/ima/ima_api.c')
| -rw-r--r-- | security/integrity/ima/ima_api.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index b37d043d5748..1856981e33df 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -245,8 +245,8 @@ int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file, const char *audit_cause = "failed"; struct inode *inode = file_inode(file); struct inode *real_inode = d_real_inode(file_dentry(file)); - const char *filename = file->f_path.dentry->d_name.name; struct ima_max_digest_data hash; + struct name_snapshot filename; struct kstat stat; int result = 0; int length; @@ -317,9 +317,13 @@ out: if (file->f_flags & O_DIRECT) audit_cause = "failed(directio)"; + take_dentry_name_snapshot(&filename, file->f_path.dentry); + integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, - filename, "collect_data", audit_cause, - result, 0); + filename.name.name, "collect_data", + audit_cause, result, 0); + + release_dentry_name_snapshot(&filename); } return result; } @@ -432,6 +436,7 @@ out: */ const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf) { + struct name_snapshot filename; char *pathname = NULL; *pathbuf = __getname(); @@ -445,7 +450,10 @@ const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf) } if (!pathname) { - strscpy(namebuf, path->dentry->d_name.name, NAME_MAX); + take_dentry_name_snapshot(&filename, path->dentry); + strscpy(namebuf, filename.name.name, NAME_MAX); + release_dentry_name_snapshot(&filename); + pathname = namebuf; } |