Bug 217613
| Summary: | [BUG] [media] dvb-usb: possible data-inconsistency due to data races in dib0700_rc_query_old_firmware() | ||
|---|---|---|---|
| Product: | Drivers | Reporter: | Tuo Li (islituo) |
| Component: | USB | Assignee: | Default virtual assignee for Drivers/USB (drivers_usb) |
| Status: | RESOLVED DUPLICATE | ||
| Severity: | normal | ||
| Priority: | P3 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | Subsystem: | ||
| Regression: | No | Bisected commit-id: | |
*** This bug has been marked as a duplicate of bug 217614 *** On Fri, Jun 30, 2023 at 01:35:28AM +0000, bugzilla-daemon@kernel.org wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=217613 > > Bug ID: 217613 > Summary: [BUG] [media] dvb-usb: possible data-inconsistency due > to data races in dib0700_rc_query_old_firmware() > Product: Drivers > Version: 2.5 > Hardware: All > OS: Linux > Status: NEW > Severity: normal > Priority: P3 > Component: USB > Assignee: drivers_usb@kernel-bugs.kernel.org > Reporter: islituo@gmail.com > Regression: No > > Our static analysis tool finds some possible data races in the > DVB USB driver in Linux 6.4.0. Please report this to the mailing lists for these drivers, not in bugzilla. thanks, greg k-h (In reply to Greg Kroah-Hartman from comment #2) > On Fri, Jun 30, 2023 at 01:35:28AM +0000, bugzilla-daemon@kernel.org wrote: > > https://bugzilla.kernel.org/show_bug.cgi?id=217613 > > > > Bug ID: 217613 > > Summary: [BUG] [media] dvb-usb: possible data-inconsistency due > > to data races in dib0700_rc_query_old_firmware() > > Product: Drivers > > Version: 2.5 > > Hardware: All > > OS: Linux > > Status: NEW > > Severity: normal > > Priority: P3 > > Component: USB > > Assignee: drivers_usb@kernel-bugs.kernel.org > > Reporter: islituo@gmail.com > > Regression: No > > > > Our static analysis tool finds some possible data races in the > > DVB USB driver in Linux 6.4.0. > > Please report this to the mailing lists for these drivers, not in > bugzilla. > > thanks, > > greg k-h Thanks for your reply! I am really sorry to bother you. I have reported this to the mailing lists for these drivers, but have not received any reply.I have resent a report to the mailing lists just now, and any feedback would be appreciated. Thanks, Tuo Li |
Our static analysis tool finds some possible data races in the DVB USB driver in Linux 6.4.0. The variable d->priv->buf is often accessed with holding the lock d->usb_mutex, here is an example: dib0700_change_protocol() --> Line 638 in dib0700_core.c st = d->priv; --> Line 641 in dib0700_core.c (Alias) mutex_lock_interruptible(&d->usb_mutex) --> Line 644 in dib0700_core.c (Lock d->usb_mutex) st->buf[0] = REQUEST_SET_RC; --> Line 649 in dib0700_core.c (Access d->priv->buf) However, in the function dib0700_rc_query_old_firmware(), the variable d->priv->buf is accessed without holding the lock d->usb_mutex: dib0700_rc_query_old_firmware() --> Line 516 in dib0700_devices.c st = d->priv; --> Line 522 in dib0700_devices.c (Alias) st->buf[0] = REQUEST_POLL_RC; --> Line 532 in dib0700_devices.c (Access st->buf) And thus harmful data races can occur because they can make data in st-buf inconsistent. I am not quite sure whether these possible data races are real and how to fix them if they are real. Any feedback would be appreciated, thanks! Reported-by: BassCheck <bass@buaa.edu.cn>