linux-kernel - bug in sscanf()?

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Date:	Thu, 9 Jan 2014 18:57:29 +0000
From:	"Allan, Bruce W" <bruce.w.allan@...el.com>
To:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:	"Allan, Bruce W" <bruce.w.allan@...el.com>
Subject: bug in sscanf()?

The kernel version of sscanf() does not allow for scanning a string with multiple concatenated integers even when maximum field widths are specified to stop reading the string to delineate the individual integers.  For example, trying to read the (3) 32-bit hexadecimal integers deadbeef, 12345678 and deadc0de when provided as a concatenated string with:

	int num;
	u32 i, j, k;

	num = sscanf("deadbeef12345678deadc0de", "%8x%8x%8x", &i, &j, &k);

will return the number of input items successfully matched and assigned as 3, the 32-bit integers j and k will have the expected values, but i will be 0.

The libc version of sscanf(), however, will set the value of i to deadbeef.

Should this be expected with the kernel version or is it a bug?

Thanks,
Bruce.

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