* [PATCH] Arch: arm: plat-pxa - Fix possible NULL derefrence. [not found] <CGME20170130045842epcas2p274b2125a1f158e4d656096bdf3a3a1d9@epcas2p2.samsung.com> @ 2017-01-30 4:58 ` Shailendra Verma 0 siblings, 0 replies; 4+ messages in thread From: Shailendra Verma @ 2017-01-30 4:58 UTC (permalink / raw) To: Russell King, linux-arm-kernel, linux-kernel, p.shailesh, ashish.kalra, Shailendra Verma, Shailendra Verma of_match_device could return NULL, and so can cause a NULL pointer dereference later. Signed-off-by: Shailendra Verma <shailendra.v@samsung.com> --- arch/arm/plat-pxa/ssp.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm/plat-pxa/ssp.c b/arch/arm/plat-pxa/ssp.c index ba13f79..7d1cd51 100644 --- a/arch/arm/plat-pxa/ssp.c +++ b/arch/arm/plat-pxa/ssp.c @@ -204,6 +204,10 @@ static int pxa_ssp_probe(struct platform_device *pdev) if (dev->of_node) { const struct of_device_id *id = of_match_device(of_match_ptr(pxa_ssp_of_ids), dev); + if (!id) { + dev_err(dev, "Error: No device match found\n"); + return -ENODEV; + } ssp->type = (int) id->data; } else { const struct platform_device_id *id = -- 1.7.9.5 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH] Arch: arm: plat-pxa - Fix possible NULL derefrence. @ 2017-01-30 4:58 ` Shailendra Verma 0 siblings, 0 replies; 4+ messages in thread From: Shailendra Verma @ 2017-01-30 4:58 UTC (permalink / raw) To: linux-arm-kernel of_match_device could return NULL, and so can cause a NULL pointer dereference later. Signed-off-by: Shailendra Verma <shailendra.v@samsung.com> --- arch/arm/plat-pxa/ssp.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm/plat-pxa/ssp.c b/arch/arm/plat-pxa/ssp.c index ba13f79..7d1cd51 100644 --- a/arch/arm/plat-pxa/ssp.c +++ b/arch/arm/plat-pxa/ssp.c @@ -204,6 +204,10 @@ static int pxa_ssp_probe(struct platform_device *pdev) if (dev->of_node) { const struct of_device_id *id = of_match_device(of_match_ptr(pxa_ssp_of_ids), dev); + if (!id) { + dev_err(dev, "Error: No device match found\n"); + return -ENODEV; + } ssp->type = (int) id->data; } else { const struct platform_device_id *id = -- 1.7.9.5 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] Arch: arm: plat-pxa - Fix possible NULL derefrence. 2017-01-30 4:58 ` Shailendra Verma @ 2017-01-30 19:08 ` Russell King - ARM Linux -1 siblings, 0 replies; 4+ messages in thread From: Russell King - ARM Linux @ 2017-01-30 19:08 UTC (permalink / raw) To: Shailendra Verma Cc: linux-arm-kernel, linux-kernel, p.shailesh, ashish.kalra, Shailendra Verma On Mon, Jan 30, 2017 at 10:28:31AM +0530, Shailendra Verma wrote: > of_match_device could return NULL, and so can cause a NULL > pointer dereference later. Please explain how this can happen. The driver is matched to the device via the driver model looking up the compatible string in the match table: .of_match_table = of_match_ptr(pxa_ssp_of_ids), It then calls the probe function, which notices that there's a DT node pointer, and the driver looks the device up in the very same table. If the driver model found a match and then the device driver didn't for the very same device, something really bad went wrong. So, if you want to add something: if (WARN_ON(!id)) return -ENODEV; should be about it, since it's something we expect to never encounter. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH] Arch: arm: plat-pxa - Fix possible NULL derefrence. @ 2017-01-30 19:08 ` Russell King - ARM Linux 0 siblings, 0 replies; 4+ messages in thread From: Russell King - ARM Linux @ 2017-01-30 19:08 UTC (permalink / raw) To: linux-arm-kernel On Mon, Jan 30, 2017 at 10:28:31AM +0530, Shailendra Verma wrote: > of_match_device could return NULL, and so can cause a NULL > pointer dereference later. Please explain how this can happen. The driver is matched to the device via the driver model looking up the compatible string in the match table: .of_match_table = of_match_ptr(pxa_ssp_of_ids), It then calls the probe function, which notices that there's a DT node pointer, and the driver looks the device up in the very same table. If the driver model found a match and then the device driver didn't for the very same device, something really bad went wrong. So, if you want to add something: if (WARN_ON(!id)) return -ENODEV; should be about it, since it's something we expect to never encounter. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net. ^ permalink raw reply [flat|nested] 4+ messages in thread
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[not found] <CGME20170130045842epcas2p274b2125a1f158e4d656096bdf3a3a1d9@epcas2p2.samsung.com>
2017-01-30 4:58 ` [PATCH] Arch: arm: plat-pxa - Fix possible NULL derefrence Shailendra Verma
2017-01-30 4:58 ` Shailendra Verma
2017-01-30 19:08 ` Russell King - ARM Linux
2017-01-30 19:08 ` Russell King - ARM Linux
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