| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 117/312] serial: samsung: Fix possible out of bounds access on non-DT platform | Date | Fri, 8 May 2020 14:31:48 +0200 |
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From: Krzysztof Kozlowski <k.kozlowski@samsung.com>
commit 926b7b5122c96e1f18cd20e85a286c7ec8d18c97 upstream.
On non-DeviceTree platforms, the index of serial device is a static variable incremented on each probe. It is incremented even if deferred probe happens when getting the clock in s3c24xx_serial_init_port().
This index is used for referencing elements of statically allocated s3c24xx_serial_ports array. In case of re-probe, the index will point outside of this array leading to memory corruption.
Increment the index only on successful probe.
Reported-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Fixes: b497549a035c ("[ARM] S3C24XX: Split serial driver into core and per-cpu drivers") Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/tty/serial/samsung.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/tty/serial/samsung.c +++ b/drivers/tty/serial/samsung.c @@ -1841,8 +1841,6 @@ static int s3c24xx_serial_probe(struct p ourport->min_dma_size = max_t(int, ourport->port.fifosize, dma_get_cache_alignment()); - probe_index++; - dbg("%s: initialising port %p...\n", __func__, ourport); ret = s3c24xx_serial_init_port(ourport, pdev); @@ -1872,6 +1870,8 @@ static int s3c24xx_serial_probe(struct p if (ret < 0) dev_err(&pdev->dev, "failed to add cpufreq notifier\n"); + probe_index++; + return 0; }
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