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 | |
| parent | 9026a8d6da2f5a283b988f0748e6324467e12636 (diff) | |
| download | history-4b4b699dc55425eb582fb233b7815ce0ecd97147.tar.gz | |
[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')
| -rw-r--r-- | fs/exec.c | 23 | ||||
| -rw-r--r-- | fs/proc/array.c | 11 |
2 files changed, 28 insertions, 6 deletions
diff --git a/fs/exec.c b/fs/exec.c index be4366c0a01192..92b788cd4394b1 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(); diff --git a/fs/proc/array.c b/fs/proc/array.c index fe14439309ab3b..995080fd88d236 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -88,10 +88,13 @@ static inline char * task_name(struct task_struct *p, char * buf) { int i; char * name; + char tcomm[sizeof(p->comm)]; + + get_task_comm(tcomm, p); ADDBUF(buf, "Name:\t"); - name = p->comm; - i = sizeof(p->comm); + name = tcomm; + i = sizeof(tcomm); do { unsigned char c = *name; name++; @@ -309,6 +312,7 @@ int proc_pid_stat(struct task_struct *task, char * buffer) int num_threads = 0; struct mm_struct *mm; unsigned long long start_time; + char tcomm[sizeof(task->comm)]; state = *get_task_state(task); vsize = eip = esp = 0; @@ -325,6 +329,7 @@ int proc_pid_stat(struct task_struct *task, char * buffer) up_read(&mm->mmap_sem); } + get_task_comm(tcomm, task); wchan = get_wchan(task); sigemptyset(&sigign); @@ -362,7 +367,7 @@ int proc_pid_stat(struct task_struct *task, char * buffer) %lu %lu %lu %lu %lu %ld %ld %ld %ld %d %ld %llu %lu %ld %lu %lu %lu %lu %lu \ %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu\n", task->pid, - task->comm, + tcomm, state, ppid, pgid, |