* [bug report] fanotify: fix copy_event_to_user() fid error clean up
@ 2021-07-21 12:54 Dan Carpenter
2021-07-21 22:38 ` Matthew Bobrowski
0 siblings, 1 reply; 6+ messages in thread
From: Dan Carpenter @ 2021-07-21 12:54 UTC (permalink / raw)
To: repnop; +Cc: Amir Goldstein, linux-fsdevel
Hello Matthew Bobrowski,
The patch f644bc449b37: "fanotify: fix copy_event_to_user() fid error
clean up" from Jun 11, 2021, leads to the following static checker
warning:
fs/notify/fanotify/fanotify_user.c:533 copy_event_to_user()
error: we previously assumed 'f' could be null (see line 462)
fs/notify/fanotify/fanotify_user.c
401 static ssize_t copy_event_to_user(struct fsnotify_group *group,
402 struct fanotify_event *event,
403 char __user *buf, size_t count)
404 {
405 struct fanotify_event_metadata metadata;
406 struct path *path = fanotify_event_path(event);
407 struct fanotify_info *info = fanotify_event_info(event);
408 unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
409 struct file *f = NULL;
410 int ret, fd = FAN_NOFD;
411 int info_type = 0;
412
413 pr_debug("%s: group=%p event=%p\n", __func__, group, event);
414
415 metadata.event_len = FAN_EVENT_METADATA_LEN +
416 fanotify_event_info_len(fid_mode, event);
417 metadata.metadata_len = FAN_EVENT_METADATA_LEN;
418 metadata.vers = FANOTIFY_METADATA_VERSION;
419 metadata.reserved = 0;
420 metadata.mask = event->mask & FANOTIFY_OUTGOING_EVENTS;
421 metadata.pid = pid_vnr(event->pid);
422 /*
423 * For an unprivileged listener, event->pid can be used to identify the
424 * events generated by the listener process itself, without disclosing
425 * the pids of other processes.
426 */
427 if (FAN_GROUP_FLAG(group, FANOTIFY_UNPRIV) &&
428 task_tgid(current) != event->pid)
429 metadata.pid = 0;
430
431 /*
432 * For now, fid mode is required for an unprivileged listener and
433 * fid mode does not report fd in events. Keep this check anyway
434 * for safety in case fid mode requirement is relaxed in the future
435 * to allow unprivileged listener to get events with no fd and no fid.
436 */
437 if (!FAN_GROUP_FLAG(group, FANOTIFY_UNPRIV) &&
438 path && path->mnt && path->dentry) {
439 fd = create_fd(group, path, &f);
440 if (fd < 0)
441 return fd;
442 }
"f" is NULL on the else path
443 metadata.fd = fd;
444
445 ret = -EFAULT;
446 /*
447 * Sanity check copy size in case get_one_event() and
448 * event_len sizes ever get out of sync.
449 */
450 if (WARN_ON_ONCE(metadata.event_len > count))
451 goto out_close_fd;
452
453 if (copy_to_user(buf, &metadata, FAN_EVENT_METADATA_LEN))
454 goto out_close_fd;
^^^^^^^^^^^^^^^^^
This is problematic
455
456 buf += FAN_EVENT_METADATA_LEN;
457 count -= FAN_EVENT_METADATA_LEN;
458
459 if (fanotify_is_perm_event(event->mask))
460 FANOTIFY_PERM(event)->fd = fd;
461
462 if (f)
^^^
463 fd_install(fd, f);
464
465 /* Event info records order is: dir fid + name, child fid */
466 if (fanotify_event_dir_fh_len(event)) {
467 info_type = info->name_len ? FAN_EVENT_INFO_TYPE_DFID_NAME :
468 FAN_EVENT_INFO_TYPE_DFID;
469 ret = copy_info_to_user(fanotify_event_fsid(event),
470 fanotify_info_dir_fh(info),
471 info_type, fanotify_info_name(info),
472 info->name_len, buf, count);
473 if (ret < 0)
474 goto out_close_fd;
475
476 buf += ret;
477 count -= ret;
478 }
479
480 if (fanotify_event_object_fh_len(event)) {
481 const char *dot = NULL;
482 int dot_len = 0;
483
484 if (fid_mode == FAN_REPORT_FID || info_type) {
485 /*
486 * With only group flag FAN_REPORT_FID only type FID is
487 * reported. Second info record type is always FID.
488 */
489 info_type = FAN_EVENT_INFO_TYPE_FID;
490 } else if ((fid_mode & FAN_REPORT_NAME) &&
491 (event->mask & FAN_ONDIR)) {
492 /*
493 * With group flag FAN_REPORT_NAME, if name was not
494 * recorded in an event on a directory, report the
495 * name "." with info type DFID_NAME.
496 */
497 info_type = FAN_EVENT_INFO_TYPE_DFID_NAME;
498 dot = ".";
499 dot_len = 1;
500 } else if ((event->mask & ALL_FSNOTIFY_DIRENT_EVENTS) ||
501 (event->mask & FAN_ONDIR)) {
502 /*
503 * With group flag FAN_REPORT_DIR_FID, a single info
504 * record has type DFID for directory entry modification
505 * event and for event on a directory.
506 */
507 info_type = FAN_EVENT_INFO_TYPE_DFID;
508 } else {
509 /*
510 * With group flags FAN_REPORT_DIR_FID|FAN_REPORT_FID,
511 * a single info record has type FID for event on a
512 * non-directory, when there is no directory to report.
513 * For example, on FAN_DELETE_SELF event.
514 */
515 info_type = FAN_EVENT_INFO_TYPE_FID;
516 }
517
518 ret = copy_info_to_user(fanotify_event_fsid(event),
519 fanotify_event_object_fh(event),
520 info_type, dot, dot_len, buf, count);
521 if (ret < 0)
522 goto out_close_fd;
^^^^^^^^^^^^^^^^^
523
524 buf += ret;
525 count -= ret;
526 }
527
528 return metadata.event_len;
529
530 out_close_fd:
531 if (fd != FAN_NOFD) {
532 put_unused_fd(fd);
--> 533 fput(f);
^^^^^^^
This leads to a NULL dereference
534 }
535 return ret;
536 }
regards,
dan carpenter
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [bug report] fanotify: fix copy_event_to_user() fid error clean up
2021-07-21 12:54 [bug report] fanotify: fix copy_event_to_user() fid error clean up Dan Carpenter
@ 2021-07-21 22:38 ` Matthew Bobrowski
2021-07-22 9:01 ` Amir Goldstein
0 siblings, 1 reply; 6+ messages in thread
From: Matthew Bobrowski @ 2021-07-21 22:38 UTC (permalink / raw)
To: Dan Carpenter; +Cc: Amir Goldstein, linux-fsdevel
On Wed, Jul 21, 2021 at 05:54:07AM -0700, Dan Carpenter wrote:
> Hello Matthew Bobrowski,
>
> The patch f644bc449b37: "fanotify: fix copy_event_to_user() fid error
> clean up" from Jun 11, 2021, leads to the following static checker
> warning:
>
> fs/notify/fanotify/fanotify_user.c:533 copy_event_to_user()
> error: we previously assumed 'f' could be null (see line 462)
I've made a couple comments below. What am I missing?
> fs/notify/fanotify/fanotify_user.c
> 401 static ssize_t copy_event_to_user(struct fsnotify_group *group,
> 402 struct fanotify_event *event,
> 403 char __user *buf, size_t count)
> 404 {
> 405 struct fanotify_event_metadata metadata;
> 406 struct path *path = fanotify_event_path(event);
> 407 struct fanotify_info *info = fanotify_event_info(event);
> 408 unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
> 409 struct file *f = NULL;
> 410 int ret, fd = FAN_NOFD;
> 411 int info_type = 0;
> 412
> 413 pr_debug("%s: group=%p event=%p\n", __func__, group, event);
> 414
> 415 metadata.event_len = FAN_EVENT_METADATA_LEN +
> 416 fanotify_event_info_len(fid_mode, event);
> 417 metadata.metadata_len = FAN_EVENT_METADATA_LEN;
> 418 metadata.vers = FANOTIFY_METADATA_VERSION;
> 419 metadata.reserved = 0;
> 420 metadata.mask = event->mask & FANOTIFY_OUTGOING_EVENTS;
> 421 metadata.pid = pid_vnr(event->pid);
> 422 /*
> 423 * For an unprivileged listener, event->pid can be used to identify the
> 424 * events generated by the listener process itself, without disclosing
> 425 * the pids of other processes.
> 426 */
> 427 if (FAN_GROUP_FLAG(group, FANOTIFY_UNPRIV) &&
> 428 task_tgid(current) != event->pid)
> 429 metadata.pid = 0;
> 430
> 431 /*
> 432 * For now, fid mode is required for an unprivileged listener and
> 433 * fid mode does not report fd in events. Keep this check anyway
> 434 * for safety in case fid mode requirement is relaxed in the future
> 435 * to allow unprivileged listener to get events with no fd and no fid.
> 436 */
> 437 if (!FAN_GROUP_FLAG(group, FANOTIFY_UNPRIV) &&
> 438 path && path->mnt && path->dentry) {
> 439 fd = create_fd(group, path, &f);
> 440 if (fd < 0)
> 441 return fd;
> 442 }
>
> "f" is NULL on the else path
Uh ha, although "fd" on the else path also remains set to the initial value
of FAN_NOFD, right?
> 443 metadata.fd = fd;
> 444
> 445 ret = -EFAULT;
> 446 /*
> 447 * Sanity check copy size in case get_one_event() and
> 448 * event_len sizes ever get out of sync.
> 449 */
> 450 if (WARN_ON_ONCE(metadata.event_len > count))
> 451 goto out_close_fd;
> 452
> 453 if (copy_to_user(buf, &metadata, FAN_EVENT_METADATA_LEN))
> 454 goto out_close_fd;
> ^^^^^^^^^^^^^^^^^
> This is problematic
>
> 455
> 456 buf += FAN_EVENT_METADATA_LEN;
> 457 count -= FAN_EVENT_METADATA_LEN;
> 458
> 459 if (fanotify_is_perm_event(event->mask))
> 460 FANOTIFY_PERM(event)->fd = fd;
> 461
> 462 if (f)
> ^^^
>
> 463 fd_install(fd, f);
> 464
> 465 /* Event info records order is: dir fid + name, child fid */
> 466 if (fanotify_event_dir_fh_len(event)) {
> 467 info_type = info->name_len ? FAN_EVENT_INFO_TYPE_DFID_NAME :
> 468 FAN_EVENT_INFO_TYPE_DFID;
> 469 ret = copy_info_to_user(fanotify_event_fsid(event),
> 470 fanotify_info_dir_fh(info),
> 471 info_type, fanotify_info_name(info),
> 472 info->name_len, buf, count);
> 473 if (ret < 0)
> 474 goto out_close_fd;
> 475
> 476 buf += ret;
> 477 count -= ret;
> 478 }
> 479
> 480 if (fanotify_event_object_fh_len(event)) {
> 481 const char *dot = NULL;
> 482 int dot_len = 0;
> 483
> 484 if (fid_mode == FAN_REPORT_FID || info_type) {
> 485 /*
> 486 * With only group flag FAN_REPORT_FID only type FID is
> 487 * reported. Second info record type is always FID.
> 488 */
> 489 info_type = FAN_EVENT_INFO_TYPE_FID;
> 490 } else if ((fid_mode & FAN_REPORT_NAME) &&
> 491 (event->mask & FAN_ONDIR)) {
> 492 /*
> 493 * With group flag FAN_REPORT_NAME, if name was not
> 494 * recorded in an event on a directory, report the
> 495 * name "." with info type DFID_NAME.
> 496 */
> 497 info_type = FAN_EVENT_INFO_TYPE_DFID_NAME;
> 498 dot = ".";
> 499 dot_len = 1;
> 500 } else if ((event->mask & ALL_FSNOTIFY_DIRENT_EVENTS) ||
> 501 (event->mask & FAN_ONDIR)) {
> 502 /*
> 503 * With group flag FAN_REPORT_DIR_FID, a single info
> 504 * record has type DFID for directory entry modification
> 505 * event and for event on a directory.
> 506 */
> 507 info_type = FAN_EVENT_INFO_TYPE_DFID;
> 508 } else {
> 509 /*
> 510 * With group flags FAN_REPORT_DIR_FID|FAN_REPORT_FID,
> 511 * a single info record has type FID for event on a
> 512 * non-directory, when there is no directory to report.
> 513 * For example, on FAN_DELETE_SELF event.
> 514 */
> 515 info_type = FAN_EVENT_INFO_TYPE_FID;
> 516 }
> 517
> 518 ret = copy_info_to_user(fanotify_event_fsid(event),
> 519 fanotify_event_object_fh(event),
> 520 info_type, dot, dot_len, buf, count);
> 521 if (ret < 0)
> 522 goto out_close_fd;
> ^^^^^^^^^^^^^^^^^
>
>
> 523
> 524 buf += ret;
> 525 count -= ret;
> 526 }
> 527
> 528 return metadata.event_len;
> 529
> 530 out_close_fd:
> 531 if (fd != FAN_NOFD) {
> 532 put_unused_fd(fd);
> --> 533 fput(f);
> ^^^^^^^
> This leads to a NULL dereference
Sure would, however if the intial else path is taken above skipping
create_fd() then "fd" would remain set to FAN_NOFD and "f" would remain set
to NULL, then this branch would not be taken and thus not leading to a NULL
dereference?
To make things clearer, avoid any future confusion and possibly tripping
over such a bug, perhaps it'd be better to split up the fput(f) call into a
separate branch outside of the current conditional, simply i.e.
...
if (f)
fput(f);
...
Thoughts?
> 534 }
> 535 return ret;
> 536 }
/M
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [bug report] fanotify: fix copy_event_to_user() fid error clean up
2021-07-21 22:38 ` Matthew Bobrowski
@ 2021-07-22 9:01 ` Amir Goldstein
2021-07-22 9:31 ` Dan Carpenter
0 siblings, 1 reply; 6+ messages in thread
From: Amir Goldstein @ 2021-07-22 9:01 UTC (permalink / raw)
To: Matthew Bobrowski; +Cc: Dan Carpenter, linux-fsdevel
On Thu, Jul 22, 2021 at 1:39 AM Matthew Bobrowski <repnop@google.com> wrote:
>
> On Wed, Jul 21, 2021 at 05:54:07AM -0700, Dan Carpenter wrote:
> > Hello Matthew Bobrowski,
> >
> > The patch f644bc449b37: "fanotify: fix copy_event_to_user() fid error
> > clean up" from Jun 11, 2021, leads to the following static checker
> > warning:
> >
> > fs/notify/fanotify/fanotify_user.c:533 copy_event_to_user()
> > error: we previously assumed 'f' could be null (see line 462)
>
> I've made a couple comments below. What am I missing?
>
> > fs/notify/fanotify/fanotify_user.c
> > 401 static ssize_t copy_event_to_user(struct fsnotify_group *group,
> > 402 struct fanotify_event *event,
> > 403 char __user *buf, size_t count)
> > 404 {
> > 405 struct fanotify_event_metadata metadata;
> > 406 struct path *path = fanotify_event_path(event);
> > 407 struct fanotify_info *info = fanotify_event_info(event);
> > 408 unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
> > 409 struct file *f = NULL;
> > 410 int ret, fd = FAN_NOFD;
> > 411 int info_type = 0;
> > 412
> > 413 pr_debug("%s: group=%p event=%p\n", __func__, group, event);
> > 414
> > 415 metadata.event_len = FAN_EVENT_METADATA_LEN +
> > 416 fanotify_event_info_len(fid_mode, event);
> > 417 metadata.metadata_len = FAN_EVENT_METADATA_LEN;
> > 418 metadata.vers = FANOTIFY_METADATA_VERSION;
> > 419 metadata.reserved = 0;
> > 420 metadata.mask = event->mask & FANOTIFY_OUTGOING_EVENTS;
> > 421 metadata.pid = pid_vnr(event->pid);
> > 422 /*
> > 423 * For an unprivileged listener, event->pid can be used to identify the
> > 424 * events generated by the listener process itself, without disclosing
> > 425 * the pids of other processes.
> > 426 */
> > 427 if (FAN_GROUP_FLAG(group, FANOTIFY_UNPRIV) &&
> > 428 task_tgid(current) != event->pid)
> > 429 metadata.pid = 0;
> > 430
> > 431 /*
> > 432 * For now, fid mode is required for an unprivileged listener and
> > 433 * fid mode does not report fd in events. Keep this check anyway
> > 434 * for safety in case fid mode requirement is relaxed in the future
> > 435 * to allow unprivileged listener to get events with no fd and no fid.
> > 436 */
> > 437 if (!FAN_GROUP_FLAG(group, FANOTIFY_UNPRIV) &&
> > 438 path && path->mnt && path->dentry) {
> > 439 fd = create_fd(group, path, &f);
> > 440 if (fd < 0)
> > 441 return fd;
> > 442 }
> >
> > "f" is NULL on the else path
>
> Uh ha, although "fd" on the else path also remains set to the initial value
> of FAN_NOFD, right?
>
> > 443 metadata.fd = fd;
> > 444
> > 445 ret = -EFAULT;
> > 446 /*
> > 447 * Sanity check copy size in case get_one_event() and
> > 448 * event_len sizes ever get out of sync.
> > 449 */
> > 450 if (WARN_ON_ONCE(metadata.event_len > count))
> > 451 goto out_close_fd;
> > 452
> > 453 if (copy_to_user(buf, &metadata, FAN_EVENT_METADATA_LEN))
> > 454 goto out_close_fd;
> > ^^^^^^^^^^^^^^^^^
> > This is problematic
> >
> > 455
> > 456 buf += FAN_EVENT_METADATA_LEN;
> > 457 count -= FAN_EVENT_METADATA_LEN;
> > 458
> > 459 if (fanotify_is_perm_event(event->mask))
> > 460 FANOTIFY_PERM(event)->fd = fd;
> > 461
> > 462 if (f)
> > ^^^
> >
> > 463 fd_install(fd, f);
> > 464
> > 465 /* Event info records order is: dir fid + name, child fid */
> > 466 if (fanotify_event_dir_fh_len(event)) {
> > 467 info_type = info->name_len ? FAN_EVENT_INFO_TYPE_DFID_NAME :
> > 468 FAN_EVENT_INFO_TYPE_DFID;
> > 469 ret = copy_info_to_user(fanotify_event_fsid(event),
> > 470 fanotify_info_dir_fh(info),
> > 471 info_type, fanotify_info_name(info),
> > 472 info->name_len, buf, count);
> > 473 if (ret < 0)
> > 474 goto out_close_fd;
> > 475
> > 476 buf += ret;
> > 477 count -= ret;
> > 478 }
> > 479
> > 480 if (fanotify_event_object_fh_len(event)) {
> > 481 const char *dot = NULL;
> > 482 int dot_len = 0;
> > 483
> > 484 if (fid_mode == FAN_REPORT_FID || info_type) {
> > 485 /*
> > 486 * With only group flag FAN_REPORT_FID only type FID is
> > 487 * reported. Second info record type is always FID.
> > 488 */
> > 489 info_type = FAN_EVENT_INFO_TYPE_FID;
> > 490 } else if ((fid_mode & FAN_REPORT_NAME) &&
> > 491 (event->mask & FAN_ONDIR)) {
> > 492 /*
> > 493 * With group flag FAN_REPORT_NAME, if name was not
> > 494 * recorded in an event on a directory, report the
> > 495 * name "." with info type DFID_NAME.
> > 496 */
> > 497 info_type = FAN_EVENT_INFO_TYPE_DFID_NAME;
> > 498 dot = ".";
> > 499 dot_len = 1;
> > 500 } else if ((event->mask & ALL_FSNOTIFY_DIRENT_EVENTS) ||
> > 501 (event->mask & FAN_ONDIR)) {
> > 502 /*
> > 503 * With group flag FAN_REPORT_DIR_FID, a single info
> > 504 * record has type DFID for directory entry modification
> > 505 * event and for event on a directory.
> > 506 */
> > 507 info_type = FAN_EVENT_INFO_TYPE_DFID;
> > 508 } else {
> > 509 /*
> > 510 * With group flags FAN_REPORT_DIR_FID|FAN_REPORT_FID,
> > 511 * a single info record has type FID for event on a
> > 512 * non-directory, when there is no directory to report.
> > 513 * For example, on FAN_DELETE_SELF event.
> > 514 */
> > 515 info_type = FAN_EVENT_INFO_TYPE_FID;
> > 516 }
> > 517
> > 518 ret = copy_info_to_user(fanotify_event_fsid(event),
> > 519 fanotify_event_object_fh(event),
> > 520 info_type, dot, dot_len, buf, count);
> > 521 if (ret < 0)
> > 522 goto out_close_fd;
> > ^^^^^^^^^^^^^^^^^
> >
> >
> > 523
> > 524 buf += ret;
> > 525 count -= ret;
> > 526 }
> > 527
> > 528 return metadata.event_len;
> > 529
> > 530 out_close_fd:
> > 531 if (fd != FAN_NOFD) {
> > 532 put_unused_fd(fd);
> > --> 533 fput(f);
> > ^^^^^^^
> > This leads to a NULL dereference
>
> Sure would, however if the intial else path is taken above skipping
> create_fd() then "fd" would remain set to FAN_NOFD and "f" would remain set
> to NULL, then this branch would not be taken and thus not leading to a NULL
> dereference?
>
> To make things clearer, avoid any future confusion and possibly tripping
> over such a bug, perhaps it'd be better to split up the fput(f) call into a
> separate branch outside of the current conditional, simply i.e.
>
> ...
>
> if (f)
> fput(f);
>
> ...
>
> Thoughts?
smatch (apparently) does not know about the relation that f is non NULL
if (fd == FAN_NOFD) it needs to study create_fd() for that.
I suggest to move fd_install(fd, f); right after checking of return value
from create_fd() and without the if (f) condition.
That should make it clear for human and robots reading this function
that the cleanup in out_close_fd label is correct.
Thanks,
Amir.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [bug report] fanotify: fix copy_event_to_user() fid error clean up
2021-07-22 9:01 ` Amir Goldstein
@ 2021-07-22 9:31 ` Dan Carpenter
2021-07-22 14:01 ` Dan Carpenter
0 siblings, 1 reply; 6+ messages in thread
From: Dan Carpenter @ 2021-07-22 9:31 UTC (permalink / raw)
To: Amir Goldstein; +Cc: Matthew Bobrowski, linux-fsdevel
On Thu, Jul 22, 2021 at 12:01:41PM +0300, Amir Goldstein wrote:
> On Thu, Jul 22, 2021 at 1:39 AM Matthew Bobrowski <repnop@google.com> wrote:
> > To make things clearer, avoid any future confusion and possibly tripping
> > over such a bug, perhaps it'd be better to split up the fput(f) call into a
> > separate branch outside of the current conditional, simply i.e.
> >
> > ...
> >
> > if (f)
> > fput(f);
> >
> > ...
> >
> > Thoughts?
>
> smatch (apparently) does not know about the relation that f is non NULL
> if (fd == FAN_NOFD) it needs to study create_fd() for that.
>
> I suggest to move fd_install(fd, f); right after checking of return value
> from create_fd() and without the if (f) condition.
> That should make it clear for human and robots reading this function
> that the cleanup in out_close_fd label is correct.
Yeah. I got "f" and "fd" mixed up in my head when I was reviewing this
code. My bad.
Smatch is *supposed* to know about the relationship between those two.
The bug is actually that Smatch records in the database that create_fd()
always fails. It's a serious bug, and I'm trying to investigate what's
going on and I'm sure that I will fix this before the end of the week.
No need to change the code just to work around a static checker bug.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [bug report] fanotify: fix copy_event_to_user() fid error clean up
2021-07-22 9:31 ` Dan Carpenter
@ 2021-07-22 14:01 ` Dan Carpenter
2021-07-22 23:13 ` Matthew Bobrowski
0 siblings, 1 reply; 6+ messages in thread
From: Dan Carpenter @ 2021-07-22 14:01 UTC (permalink / raw)
To: Amir Goldstein; +Cc: Matthew Bobrowski, linux-fsdevel
On Thu, Jul 22, 2021 at 12:31:42PM +0300, Dan Carpenter wrote:
> Smatch is *supposed* to know about the relationship between those two.
> The bug is actually that Smatch records in the database that create_fd()
> always fails. It's a serious bug, and I'm trying to investigate what's
> going on and I'm sure that I will fix this before the end of the week.
I'm testing a Smatch fix for this so hopefully it will pushed in a few
days.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [bug report] fanotify: fix copy_event_to_user() fid error clean up
2021-07-22 14:01 ` Dan Carpenter
@ 2021-07-22 23:13 ` Matthew Bobrowski
0 siblings, 0 replies; 6+ messages in thread
From: Matthew Bobrowski @ 2021-07-22 23:13 UTC (permalink / raw)
To: Dan Carpenter; +Cc: Amir Goldstein, linux-fsdevel
On Thu, Jul 22, 2021 at 05:01:03PM +0300, Dan Carpenter wrote:
> On Thu, Jul 22, 2021 at 12:31:42PM +0300, Dan Carpenter wrote:
> > Smatch is *supposed* to know about the relationship between those two.
> > The bug is actually that Smatch records in the database that create_fd()
> > always fails. It's a serious bug, and I'm trying to investigate what's
> > going on and I'm sure that I will fix this before the end of the week.
>
> I'm testing a Smatch fix for this so hopefully it will pushed in a few
> days.
Great!
Well, do let us know what the outcome is post running the Smatch tests
against the copy_event_to_user() function once again...
I do feel as though shuffling things around isn't necessary. Especially
considering the fact that what is current is correct and as you mentioned
this is a perfect oppurtunity to make the tooling better. :)
/M
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-07-22 23:13 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-21 12:54 [bug report] fanotify: fix copy_event_to_user() fid error clean up Dan Carpenter
2021-07-21 22:38 ` Matthew Bobrowski
2021-07-22 9:01 ` Amir Goldstein
2021-07-22 9:31 ` Dan Carpenter
2021-07-22 14:01 ` Dan Carpenter
2021-07-22 23:13 ` Matthew Bobrowski
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