Re: [PATCH RFC 1/6] net: rfkill: gpio: fix gpio name buffer size off by 1
On Fri, Jan 17, 2014 at 5:46 PM, David Laight wrote: > From: Chen-Yu Tsai >> snprintf should be passed the complete size of the buffer, including >> the space for '\0'. The previous code resulted in the *_reset and >> *_shutdown strings being truncated. > ... >> diff --git a/net/rfkill/rfkill-gpio.c b/net/rfkill/rfkill-gpio.c > ... >> - snprintf(rfkill->reset_name, len + 6 , "%s_reset", rfkill->name); >> - snprintf(rfkill->shutdown_name, len + 9, "%s_shutdown", rfkill->name); >> + snprintf(rfkill->reset_name, len + 7 , "%s_reset", rfkill->name); >> + snprintf(rfkill->shutdown_name, len + 10, "%s_shutdown", rfkill->name); > > I can't find the context for the above, but they look very dubious. > I'd expect: snprintf(foo, sizeof foo, ...). > If you are trying to truncate rfkill->name you need to use %.*s. The driver allocates these buffers on the fly, a few lines above: len = strlen(rfkill->name); rfkill->reset_name = devm_kzalloc(>dev, len + 7, GFP_KERNEL); rfkill->shutdown_name = devm_kzalloc(>dev, len + 10, GFP_KERNEL); I am not trying to truncate rfkill->name. Rather, the buffer length passed to snprintf was wrong, so the resulting name was truncated by one character. Thanks, ChenYu -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
RE: [PATCH RFC 1/6] net: rfkill: gpio: fix gpio name buffer size off by 1
From: Chen-Yu Tsai > snprintf should be passed the complete size of the buffer, including > the space for '\0'. The previous code resulted in the *_reset and > *_shutdown strings being truncated. ... > diff --git a/net/rfkill/rfkill-gpio.c b/net/rfkill/rfkill-gpio.c ... > - snprintf(rfkill->reset_name, len + 6 , "%s_reset", rfkill->name); > - snprintf(rfkill->shutdown_name, len + 9, "%s_shutdown", rfkill->name); > + snprintf(rfkill->reset_name, len + 7 , "%s_reset", rfkill->name); > + snprintf(rfkill->shutdown_name, len + 10, "%s_shutdown", rfkill->name); I can't find the context for the above, but they look very dubious. I'd expect: snprintf(foo, sizeof foo, ...). If you are trying to truncate rfkill->name you need to use %.*s. David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
RE: [PATCH RFC 1/6] net: rfkill: gpio: fix gpio name buffer size off by 1
From: Chen-Yu Tsai snprintf should be passed the complete size of the buffer, including the space for '\0'. The previous code resulted in the *_reset and *_shutdown strings being truncated. ... diff --git a/net/rfkill/rfkill-gpio.c b/net/rfkill/rfkill-gpio.c ... - snprintf(rfkill-reset_name, len + 6 , %s_reset, rfkill-name); - snprintf(rfkill-shutdown_name, len + 9, %s_shutdown, rfkill-name); + snprintf(rfkill-reset_name, len + 7 , %s_reset, rfkill-name); + snprintf(rfkill-shutdown_name, len + 10, %s_shutdown, rfkill-name); I can't find the context for the above, but they look very dubious. I'd expect: snprintf(foo, sizeof foo, ...). If you are trying to truncate rfkill-name you need to use %.*s. David -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH RFC 1/6] net: rfkill: gpio: fix gpio name buffer size off by 1
On Fri, Jan 17, 2014 at 5:46 PM, David Laight david.lai...@aculab.com wrote: From: Chen-Yu Tsai snprintf should be passed the complete size of the buffer, including the space for '\0'. The previous code resulted in the *_reset and *_shutdown strings being truncated. ... diff --git a/net/rfkill/rfkill-gpio.c b/net/rfkill/rfkill-gpio.c ... - snprintf(rfkill-reset_name, len + 6 , %s_reset, rfkill-name); - snprintf(rfkill-shutdown_name, len + 9, %s_shutdown, rfkill-name); + snprintf(rfkill-reset_name, len + 7 , %s_reset, rfkill-name); + snprintf(rfkill-shutdown_name, len + 10, %s_shutdown, rfkill-name); I can't find the context for the above, but they look very dubious. I'd expect: snprintf(foo, sizeof foo, ...). If you are trying to truncate rfkill-name you need to use %.*s. The driver allocates these buffers on the fly, a few lines above: len = strlen(rfkill-name); rfkill-reset_name = devm_kzalloc(pdev-dev, len + 7, GFP_KERNEL); rfkill-shutdown_name = devm_kzalloc(pdev-dev, len + 10, GFP_KERNEL); I am not trying to truncate rfkill-name. Rather, the buffer length passed to snprintf was wrong, so the resulting name was truncated by one character. Thanks, ChenYu -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
