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authorGeert Uytterhoeven <geert+renesas@glider.be>2018-07-17 11:58:10 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-07-21 09:39:25 +0300
commit1481ecf1941a35a3e82d0f3e8fe9a2bdce28ee6f (patch)
tree5c40b71e228ac1ab106c899c60dd40217c4eb424
parentfefe287e4bf6ee23a5d9422a0a49de5389acc712 (diff)
downloadlinux-1481ecf1941a35a3e82d0f3e8fe9a2bdce28ee6f.tar.xz
serial: sh-sci: Fix use-after-free on subsequent port startup
sci_request_irq() checks port->irqstr[j] for a NULL pointer, to decide if a fallback interrupt name string should be allocated or not. While this string is freed during port shutdown, the pointer is not zeroed. Hence on a subsequent startup of the port, it will still be pointing to the freed memory, leading to e.g. WARNING: CPU: 0 PID: 404 at fs/proc/generic.c:388 __proc_create+0xbc/0x260 name len 0 or to a crash (the latter is more likely with CONFIG_DEBUG_SLAB=y, due to the poisoning of freed memory). Instead of zeroeing the pointer at multiple places, preinitialize port->irqstr[j] to zero to fix this. Fixes: 8b0bbd956228ae87 ("serial: sh-sci: Add support for R7S9210") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/tty/serial/sh-sci.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 5808edfe3f7b..f8e53ac5c17d 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1872,6 +1872,7 @@ static int sci_request_irq(struct sci_port *port)
}
desc = sci_irq_desc + i;
+ port->irqstr[j] = NULL;
if (SCIx_TEIDRI_IRQ_EXISTS(port)) {
/*
* ERI and BRI are muxed, just register ERI and