lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[PATCH] sanitize unshare_files/reset_files_struct

Browse Source 
* let unshare_files() give caller the displaced files_struct
* don't bother with grabbing reference only to drop it in the
  caller if it hadn't been shared in the first place
* in that form unshare_files() is trivially implemented via
  unshare_fd(), so we eliminate the duplicate logics in fork.c
* reset_files_struct() is not just only called for current;
  it will break the system if somebody ever calls it for anything
  else (we can't modify ->files of somebody else).  Lose the
  task_struct * argument.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2008-04-22 05:31:30 -04:00
parent fd8328be87
commit 3b1253880b
5 changed files with 34 additions and 47 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
fs/exec.c
View File

@@ -1269,19 +1269,13 @@ int do_execve(char * filename,
struct linux_binprm *bprm;
struct file *file;
unsigned long env_p;
struct files_struct *files;
struct files_struct *displaced;
int retval;
files = current->files;
retval = unshare_files();
retval = unshare_files(&displaced);
if (retval)
goto out_ret;
if (files == current->files) {
put_files_struct(files);
files = NULL;
}
retval = -ENOMEM;
bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
if (!bprm)
@@ -1340,8 +1334,8 @@ int do_execve(char * filename,
security_bprm_free(bprm);
acct_update_integrals(current);
kfree(bprm);
if (files)
put_files_struct(files);
if (displaced)
put_files_struct(displaced);
return retval;
}
@@ -1363,8 +1357,8 @@ out_kfree:
kfree(bprm);
out_files:
if (files)
reset_files_struct(current, files);
if (displaced)
reset_files_struct(displaced);
out_ret:
return retval;
}