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author | David Woodhouse <dwmw2@infradead.org> | 2009-05-18 13:07:35 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-05-18 08:37:15 -0700 |
commit | 80193195f87ebca6d7417516d6edeb3969631c15 (patch) | |
tree | 870be37dde8e7d2524c2cce5a4571d5a41f0a80a /arch/x86/kernel/ftrace.c | |
parent | dbf8c11f821b6ff83302c34f2403b4f7231f50ae (diff) | |
download | kernel-crypto-80193195f87ebca6d7417516d6edeb3969631c15.tar.gz kernel-crypto-80193195f87ebca6d7417516d6edeb3969631c15.tar.xz kernel-crypto-80193195f87ebca6d7417516d6edeb3969631c15.zip |
Fix oops on close of hot-unplugged FTDI serial converter
Commit c45d6320 ("fix reference counting of ftdi_private") stopped
ftdi_sio_port_remove() from directly freeing the port-private data, with
the intention if the port was still open, it would be freed when
ftdi_close() is eventually called and releases the last refcount on the
structure.
That's all very well, but ftdi_sio_port_remove() still contains a call
to usb_set_serial_port_data(port, NULL) -- so by the time we get to
ftdi_close() for the port which was unplugged, it _still_ oopses on
dereferencing that NULL pointer, as it did before (and does in 2.6.29).
The fix is just not to clear the private data in ftdi_sio_port_remove().
Then the refcount is properly reduced to zero when the final kref_put()
happens in ftdi_close().
Remove a bogus comment too, while we're at it. And stop doing things
inside "if (priv)" -- it must _always_ be there.
Based loosely on an earlier patch by Daniel Mack, and suggestions by
Alan Stern.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Tested-by: Daniel Mack <daniel@caiaq.de>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/kernel/ftrace.c')
0 files changed, 0 insertions, 0 deletions