diff options
| author | Mike Kravetz <kravetz@us.ibm.com> | 2004-08-22 22:26:30 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-08-22 22:26:30 -0700 |
| commit | 4b4b699dc55425eb582fb233b7815ce0ecd97147 (patch) | |
| tree | 1498a69ffae64a8b548c2c9cbadcbabe58fe744c /fs/exec.c | |
| parent | 9026a8d6da2f5a283b988f0748e6324467e12636 (diff) | |
[PATCH] proc fs task name locking fix
Races have been observed between excec-time overwriting of task->comm and
/proc accesses to the same data. This causes environment string
information to appear in /proc.
Fix that up by taking task_lock() around updates to and accesses to
task->comm.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/fs/exec.c b/fs/exec.c index be4366c0a011..92b788cd4394 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -786,11 +786,27 @@ static inline void flush_old_files(struct files_struct * files) spin_unlock(&files->file_lock); } +void get_task_comm(char *buf, struct task_struct *tsk) +{ + /* buf must be at least sizeof(tsk->comm) in size */ + task_lock(tsk); + memcpy(buf, tsk->comm, sizeof(tsk->comm)); + task_unlock(tsk); +} + +void set_task_comm(struct task_struct *tsk, char *buf) +{ + task_lock(tsk); + strlcpy(tsk->comm, buf, sizeof(tsk->comm)); + task_unlock(tsk); +} + int flush_old_exec(struct linux_binprm * bprm) { char * name; int i, ch, retval; struct files_struct *files; + char tcomm[sizeof(current->comm)]; /* * Make sure we have a private signal table and that @@ -831,10 +847,11 @@ int flush_old_exec(struct linux_binprm * bprm) if (ch == '/') i = 0; else - if (i < 15) - current->comm[i++] = ch; + if (i < (sizeof(tcomm) - 1)) + tcomm[i++] = ch; } - current->comm[i] = '\0'; + tcomm[i] = '\0'; + set_task_comm(current, tcomm); flush_thread(); |