lkml.org 
[lkml]   [2016]   [May]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v3 1/1] ovl: setxattr: don't deadlock when called from ima_fix_xattr.
From
Date
On Mon, 2016-05-30 at 17:50 +0100, Al Viro wrote:
> Only tangentially related, but... that bug had been discussed,
> without any results: the fallback in ima_d_path() to ->d_name.name is
> completely broken. There is no warranty whatsoever that dentry won't be
> renamed, with its earlier (too long to be embedded into dentry itself)
> ->d_name.name getting freed. Right under your code.

Isn't i_mutex required?

>
> Could we please get rid of that thing? "A message in a near-oom
> situation might be less informative than we'd like" is better than
> "this code might end up dereferencing freed memory".
>
> Another similar bug is in ima_collect_measurement() -
> const char *filename = file->f_path.dentry->d_name.name;
> ...
> integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
> filename, "collect_data", audit_cause,
> with no warranty whatsoever that you are not passing a pointer to freed
> memory. The same goes for ima_eventname_init_common() -
> if (event_data->file) {
> cur_filename = event_data->file->f_path.dentry->d_name.name;
> cur_filename_len = strlen(cur_filename);
> } else
> ...
> return ima_write_template_field_data(cur_filename, cur_filename_len,
> DATA_FMT_STRING, field_data);
> --
> To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>


\
 
 \ /
  Last update: 2016-05-31 04:41    [W:0.051 / U:1.328 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site