[SCSI] st: fix race in st_scsi_execute_end
authorPetr Uzel <petr.uzel@suse.cz>
Fri, 21 Oct 2011 11:31:09 +0000 (13:31 +0200)
committerJames Bottomley <JBottomley@Parallels.com>
Sun, 30 Oct 2011 09:27:28 +0000 (13:27 +0400)
commitc68bf8eeaa57c852e74adcf597237be149eef830
treebd631c9731acc98e562fe202da55b050637c203f
parent3308511c93e6ad0d3c58984ecd6e5e57f96b12c8
[SCSI] st: fix race in st_scsi_execute_end

The call to complete() in st_scsi_execute_end() wakes up sleeping thread
in write_behind_check(), which frees the st_request, thus invalidating
the pointer to the associated bio structure, which is then passed to the
blk_rq_unmap_user(). Fix by storing pointer to bio structure into
temporary local variable.

This bug is present since at least linux-2.6.32.

CC: stable@kernel.org
Signed-off-by: Petr Uzel <petr.uzel@suse.cz>
Reported-by: Juergen Groß <juergen.gross@ts.fujitsu.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
drivers/scsi/st.c