Messages in this thread Patch in this message | | | From | "Denis V. Lunev" <> | Subject | [PATCH 1/2] Crash in linux kernel when disconnecting usb storage | Date | Tue, 3 Nov 2009 12:36:35 +0300 |
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From: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
__scsi_remove_device() in scsi_forget_host() is executed out of scan_mutex and races with scsi_destroy_sdev() <- scsi_sysfs_add_devices() <- scsi_finish_async_scan(). The result is use after free and/or double free, oops.
The fix is simple, move scsi_forget_host() under scan_mutex.
scsi_forget_host() is just sequence of __scsi_remove_device(). All another calls of __scsi_remove_device() are made under scan_mutex. So that it is safe.
Signed-off-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> CC: James E.J. Bottomley <James.Bottomley@suse.de> Signed-off-by: Denis V. Lunev <den@openvz.org> --- drivers/scsi/hosts.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 5fd2da4..c968cc3 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -164,8 +164,8 @@ void scsi_remove_host(struct Scsi_Host *shost) return; } spin_unlock_irqrestore(shost->host_lock, flags); - mutex_unlock(&shost->scan_mutex); scsi_forget_host(shost); + mutex_unlock(&shost->scan_mutex); scsi_proc_host_rm(shost); spin_lock_irqsave(shost->host_lock, flags); -- 1.6.4.4
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