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authorEric W. Biederman <ebiederm@xmission.com>2006-10-02 05:17:15 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-02 10:57:14 -0400
commit609d7fa9565c754428d2520cac2accc9052e1245 (patch)
tree1c5114ec3720166fe99ce3885e8767929a8a84e0
parentbde0d2c98bcfc9acc83ac79c33a6ac1335b95a92 (diff)
[PATCH] file: modify struct fown_struct to use a struct pid
File handles can be requested to send sigio and sigurg to processes. By tracking the destination processes using struct pid instead of pid_t we make the interface safe from all potential pid wrap around problems. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--drivers/net/tun.c2
-rw-r--r--fs/dnotify.c2
-rw-r--r--fs/fcntl.c77
-rw-r--r--fs/file_table.c1
-rw-r--r--fs/locks.c2
-rw-r--r--include/linux/fs.h5
-rw-r--r--kernel/futex.c2
-rw-r--r--net/socket.c2
8 files changed, 59 insertions, 34 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index bc0face01d25..151a2e10e4f3 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -697,7 +697,7 @@ static int tun_chr_fasync(int fd, struct file *file, int on)
697 return ret; 697 return ret;
698 698
699 if (on) { 699 if (on) {
700 ret = f_setown(file, current->pid, 0); 700 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
701 if (ret) 701 if (ret)
702 return ret; 702 return ret;
703 tun->flags |= TUN_FASYNC; 703 tun->flags |= TUN_FASYNC;
diff --git a/fs/dnotify.c b/fs/dnotify.c
index f932591df5a4..2b0442db67e0 100644
--- a/fs/dnotify.c
+++ b/fs/dnotify.c
@@ -92,7 +92,7 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
92 prev = &odn->dn_next; 92 prev = &odn->dn_next;
93 } 93 }
94 94
95 error = f_setown(filp, current->pid, 0); 95 error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0);
96 if (error) 96 if (error)
97 goto out_free; 97 goto out_free;
98 98
diff --git a/fs/fcntl.c b/fs/fcntl.c
index d35cbc6bc112..e7c66a1bf831 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -250,19 +250,22 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
250 return error; 250 return error;
251} 251}
252 252
253static void f_modown(struct file *filp, unsigned long pid, 253static void f_modown(struct file *filp, struct pid *pid, enum pid_type type,
254 uid_t uid, uid_t euid, int force) 254 uid_t uid, uid_t euid, int force)
255{ 255{
256 write_lock_irq(&filp->f_owner.lock); 256 write_lock_irq(&filp->f_owner.lock);
257 if (force || !filp->f_owner.pid) { 257 if (force || !filp->f_owner.pid) {
258 filp->f_owner.pid = pid; 258 put_pid(filp->f_owner.pid);
259 filp->f_owner.pid = get_pid(pid);
260 filp->f_owner.pid_type = type;
259 filp->f_owner.uid = uid; 261 filp->f_owner.uid = uid;
260 filp->f_owner.euid = euid; 262 filp->f_owner.euid = euid;
261 } 263 }
262 write_unlock_irq(&filp->f_owner.lock); 264 write_unlock_irq(&filp->f_owner.lock);
263} 265}
264 266
265int f_setown(struct file *filp, unsigned long arg, int force) 267int __f_setown(struct file *filp, struct pid *pid, enum pid_type type,
268 int force)
266{ 269{
267 int err; 270 int err;
268 271
@@ -270,15 +273,42 @@ int f_setown(struct file *filp, unsigned long arg, int force)
270 if (err) 273 if (err)
271 return err; 274 return err;
272 275
273 f_modown(filp, arg, current->uid, current->euid, force); 276 f_modown(filp, pid, type, current->uid, current->euid, force);
274 return 0; 277 return 0;
275} 278}
279EXPORT_SYMBOL(__f_setown);
276 280
281int f_setown(struct file *filp, unsigned long arg, int force)
282{
283 enum pid_type type;
284 struct pid *pid;
285 int who = arg;
286 int result;
287 type = PIDTYPE_PID;
288 if (who < 0) {
289 type = PIDTYPE_PGID;
290 who = -who;
291 }
292 rcu_read_lock();
293 pid = find_pid(who);
294 result = __f_setown(filp, pid, type, force);
295 rcu_read_unlock();
296 return result;
297}
277EXPORT_SYMBOL(f_setown); 298EXPORT_SYMBOL(f_setown);
278 299
279void f_delown(struct file *filp) 300void f_delown(struct file *filp)
280{ 301{
281 f_modown(filp, 0, 0, 0, 1); 302 f_modown(filp, NULL, PIDTYPE_PID, 0, 0, 1);
303}
304
305pid_t f_getown(struct file *filp)
306{
307 pid_t pid;
308 pid = pid_nr(filp->f_owner.pid);
309 if (filp->f_owner.pid_type == PIDTYPE_PGID)
310 pid = -pid;
311 return pid;
282} 312}
283 313
284static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, 314static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
@@ -319,7 +349,7 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
319 * current syscall conventions, the only way 349 * current syscall conventions, the only way
320 * to fix this will be in libc. 350 * to fix this will be in libc.
321 */ 351 */
322 err = filp->f_owner.pid; 352 err = f_getown(filp);
323 force_successful_syscall_return(); 353 force_successful_syscall_return();
324 break; 354 break;
325 case F_SETOWN: 355 case F_SETOWN:
@@ -470,24 +500,19 @@ static void send_sigio_to_task(struct task_struct *p,
470void send_sigio(struct fown_struct *fown, int fd, int band) 500void send_sigio(struct fown_struct *fown, int fd, int band)
471{ 501{
472 struct task_struct *p; 502 struct task_struct *p;
473 int pid; 503 enum pid_type type;
504 struct pid *pid;
474 505
475 read_lock(&fown->lock); 506 read_lock(&fown->lock);
507 type = fown->pid_type;
476 pid = fown->pid; 508 pid = fown->pid;
477 if (!pid) 509 if (!pid)
478 goto out_unlock_fown; 510 goto out_unlock_fown;
479 511
480 read_lock(&tasklist_lock); 512 read_lock(&tasklist_lock);
481 if (pid > 0) { 513 do_each_pid_task(pid, type, p) {
482 p = find_task_by_pid(pid); 514 send_sigio_to_task(p, fown, fd, band);
483 if (p) { 515 } while_each_pid_task(pid, type, p);
484 send_sigio_to_task(p, fown, fd, band);
485 }
486 } else {
487 do_each_task_pid(-pid, PIDTYPE_PGID, p) {
488 send_sigio_to_task(p, fown, fd, band);
489 } while_each_task_pid(-pid, PIDTYPE_PGID, p);
490 }
491 read_unlock(&tasklist_lock); 516 read_unlock(&tasklist_lock);
492 out_unlock_fown: 517 out_unlock_fown:
493 read_unlock(&fown->lock); 518 read_unlock(&fown->lock);
@@ -503,9 +528,12 @@ static void send_sigurg_to_task(struct task_struct *p,
503int send_sigurg(struct fown_struct *fown) 528int send_sigurg(struct fown_struct *fown)
504{ 529{
505 struct task_struct *p; 530 struct task_struct *p;
506 int pid, ret = 0; 531 enum pid_type type;
532 struct pid *pid;
533 int ret = 0;
507 534
508 read_lock(&fown->lock); 535 read_lock(&fown->lock);
536 type = fown->pid_type;
509 pid = fown->pid; 537 pid = fown->pid;
510 if (!pid) 538 if (!pid)
511 goto out_unlock_fown; 539 goto out_unlock_fown;
@@ -513,16 +541,9 @@ int send_sigurg(struct fown_struct *fown)
513 ret = 1; 541 ret = 1;
514 542
515 read_lock(&tasklist_lock); 543 read_lock(&tasklist_lock);
516 if (pid > 0) { 544 do_each_pid_task(pid, type, p) {
517 p = find_task_by_pid(pid); 545 send_sigurg_to_task(p, fown);
518 if (p) { 546 } while_each_pid_task(pid, type, p);
519 send_sigurg_to_task(p, fown);
520 }
521 } else {
522 do_each_task_pid(-pid, PIDTYPE_PGID, p) {
523 send_sigurg_to_task(p, fown);
524 } while_each_task_pid(-pid, PIDTYPE_PGID, p);
525 }
526 read_unlock(&tasklist_lock); 547 read_unlock(&tasklist_lock);
527 out_unlock_fown: 548 out_unlock_fown:
528 read_unlock(&fown->lock); 549 read_unlock(&fown->lock);
diff --git a/fs/file_table.c b/fs/file_table.c
index bc35a40417d7..24f25a057d9c 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -174,6 +174,7 @@ void fastcall __fput(struct file *file)
174 fops_put(file->f_op); 174 fops_put(file->f_op);
175 if (file->f_mode & FMODE_WRITE) 175 if (file->f_mode & FMODE_WRITE)
176 put_write_access(inode); 176 put_write_access(inode);
177 put_pid(file->f_owner.pid);
177 file_kill(file); 178 file_kill(file);
178 file->f_dentry = NULL; 179 file->f_dentry = NULL;
179 file->f_vfsmnt = NULL; 180 file->f_vfsmnt = NULL;
diff --git a/fs/locks.c b/fs/locks.c
index 21dfadfca2bc..e0b6a80649a0 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1514,7 +1514,7 @@ int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
1514 goto out_unlock; 1514 goto out_unlock;
1515 } 1515 }
1516 1516
1517 error = f_setown(filp, current->pid, 0); 1517 error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0);
1518out_unlock: 1518out_unlock:
1519 unlock_kernel(); 1519 unlock_kernel();
1520 return error; 1520 return error;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2e29a2edaeec..91c0b2a32a90 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -684,7 +684,8 @@ extern struct block_device *I_BDEV(struct inode *inode);
684 684
685struct fown_struct { 685struct fown_struct {
686 rwlock_t lock; /* protects pid, uid, euid fields */ 686 rwlock_t lock; /* protects pid, uid, euid fields */
687 int pid; /* pid or -pgrp where SIGIO should be sent */ 687 struct pid *pid; /* pid or -pgrp where SIGIO should be sent */
688 enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */
688 uid_t uid, euid; /* uid/euid of process setting the owner */ 689 uid_t uid, euid; /* uid/euid of process setting the owner */
689 int signum; /* posix.1b rt signal to be delivered on IO */ 690 int signum; /* posix.1b rt signal to be delivered on IO */
690}; 691};
@@ -880,8 +881,10 @@ extern void kill_fasync(struct fasync_struct **, int, int);
880/* only for net: no internal synchronization */ 881/* only for net: no internal synchronization */
881extern void __kill_fasync(struct fasync_struct *, int, int); 882extern void __kill_fasync(struct fasync_struct *, int, int);
882 883
884extern int __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
883extern int f_setown(struct file *filp, unsigned long arg, int force); 885extern int f_setown(struct file *filp, unsigned long arg, int force);
884extern void f_delown(struct file *filp); 886extern void f_delown(struct file *filp);
887extern pid_t f_getown(struct file *filp);
885extern int send_sigurg(struct fown_struct *fown); 888extern int send_sigurg(struct fown_struct *fown);
886 889
887/* 890/*
diff --git a/kernel/futex.c b/kernel/futex.c
index 4b6770e9806d..4aaf91951a43 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1527,7 +1527,7 @@ static int futex_fd(u32 __user *uaddr, int signal)
1527 filp->f_mapping = filp->f_dentry->d_inode->i_mapping; 1527 filp->f_mapping = filp->f_dentry->d_inode->i_mapping;
1528 1528
1529 if (signal) { 1529 if (signal) {
1530 err = f_setown(filp, current->pid, 1); 1530 err = __f_setown(filp, task_pid(current), PIDTYPE_PID, 1);
1531 if (err < 0) { 1531 if (err < 0) {
1532 goto error; 1532 goto error;
1533 } 1533 }
diff --git a/net/socket.c b/net/socket.c
index 01918f7a301a..6c9b9b326d76 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -825,7 +825,7 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
825 break; 825 break;
826 case FIOGETOWN: 826 case FIOGETOWN:
827 case SIOCGPGRP: 827 case SIOCGPGRP:
828 err = put_user(sock->file->f_owner.pid, 828 err = put_user(f_getown(sock->file),
829 (int __user *)argp); 829 (int __user *)argp);
830 break; 830 break;
831 case SIOCGIFBR: 831 case SIOCGIFBR: