diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2016-12-11 18:31:22 +0100 |
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committer | David S. Miller <davem@davemloft.net> | 2016-12-16 13:25:06 -0500 |
commit | e28ceeb10cd1883a4b6528c17a2b1f2024e35cad (patch) | |
tree | 19b7812558e8fbef8247ed8c4dbee9ad0ca89fee /Documentation | |
parent | 3e1ed981b7a903ba81199d4d25b80c6bba705160 (diff) |
net/3com/3c515: Fix timer handling, prevent leaks and crashes
The timer handling in this driver is broken in several ways:
- corkscrew_open() initializes and arms a timer before requesting the
device interrupt. If the request fails the timer stays armed.
A second call to corkscrew_open will unconditionally reinitialize the
quued timer and arm it again. Also a immediate device removal will leave
the timer queued because close() is not called (open() failed) and
therefore nothing issues del_timer().
The reinitialization corrupts the link chain in the timer wheel hash
bucket and causes a NULL pointer dereference when the timer wheel tries
to operate on that hash bucket. Immediate device removal lets the link
chain poke into freed and possibly reused memory.
Solution: Arm the timer after the successful irq request.
- corkscrew_close() uses del_timer()
On close the timer is disarmed with del_timer() which lets the following
code race against a concurrent timer expiry function.
Solution: Use del_timer_sync() instead
- corkscrew_close() calls del_timer() unconditionally
del_timer() is invoked even if the timer was never initialized. This
works by chance because the struct containing the timer is zeroed at
allocation time.
Solution: Move the setup of the timer into corkscrew_setup().
Reported-by: Matthew Whitehead <tedheadster@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation')
0 files changed, 0 insertions, 0 deletions