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| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2018-07-17 11:58:10 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-21 09:39:25 +0300 |
| commit | 1481ecf1941a35a3e82d0f3e8fe9a2bdce28ee6f (patch) | |
| tree | 5c40b71e228ac1ab106c899c60dd40217c4eb424 /drivers/tty/serial/sh-sci.c | |
| parent | fefe287e4bf6ee23a5d9422a0a49de5389acc712 (diff) | |
| download | linux-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>
Diffstat (limited to 'drivers/tty/serial/sh-sci.c')
| -rw-r--r-- | drivers/tty/serial/sh-sci.c | 1 |
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 |