ide-cd: Do not access completed requests in the irq handler

commit 110712828365ccafcc61a7f4db44c31ed4cf8793 upstream.

ide_cd_error_cmd() can complete an erroneous request with leftover
buffers. Signal this with its return value so that the request is not
accessed after its completion in the irq handler and we oops.

Signed-off-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 64207df8da82fe5627664777518617bd0facc990..2de76cc08f61d335a816d752c0bf3d9f955ee1bc 100644 (file)
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -506,15 +506,22 @@ int ide_cd_queue_pc(ide_drive_t *drive, const unsigned char *cmd,
        return (flags & REQ_FAILED) ? -EIO : 0;
 }
 
-static void ide_cd_error_cmd(ide_drive_t *drive, struct ide_cmd *cmd)
+/*
+ * returns true if rq has been completed
+ */
+static bool ide_cd_error_cmd(ide_drive_t *drive, struct ide_cmd *cmd)
 {
        unsigned int nr_bytes = cmd->nbytes - cmd->nleft;
 
        if (cmd->tf_flags & IDE_TFLAG_WRITE)
                nr_bytes -= cmd->last_xfer_len;
 
-       if (nr_bytes > 0)
+       if (nr_bytes > 0) {
                ide_complete_rq(drive, 0, nr_bytes);
+               return true;
+       }
+
+       return false;
 }
 
 static ide_startstop_t cdrom_newpc_intr(ide_drive_t *drive)
@@ -679,7 +686,8 @@ out_end:
                }
 
                if (uptodate == 0 && rq->bio)
-                       ide_cd_error_cmd(drive, cmd);
+                       if (ide_cd_error_cmd(drive, cmd))
+                               return ide_stopped;
 
                /* make sure it's fully ended */
                if (blk_fs_request(rq) == 0) {