Messages in this thread | | | Date | Tue, 17 Jul 2018 14:17:53 +0200 | From | Simon Horman <> | Subject | Re: [PATCH] serial: sh-sci: Fix use-after-free on subsequent port startup |
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On Tue, Jul 17, 2018 at 10:58:10AM +0200, Geert Uytterhoeven wrote: > 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: Simon Horman <horms+renesas@verge.net.au>
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