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Commit f08b1826 authored by Alexander Shishkin's avatar Alexander Shishkin Committed by Greg Kroah-Hartman
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stm class: Prevent user-controllable allocations 



Currently, the character device write method allocates a temporary buffer
for user's data, but the user's data size is not sanitized and can cause
arbitrarily large allocations via kzalloc() or an integer overflow that
will then result in overwriting kernel memory.

This patch trims the input buffer size to avoid these issues.

Reported-by: default avatarSasha Levin <sasha.levin@oracle.com>
Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7b3bb0e7

drivers/hwtracing/stm/core.c

+3 −0
Original line number Diff line number Diff line
@@ -406,6 +406,9 @@ static ssize_t stm_char_write(struct file *file, const char __user *buf, 
	char *kbuf;

	int err;



	if (count + 1 > PAGE_SIZE)

		count = PAGE_SIZE - 1;



	/*

	 * if no m/c have been assigned to this writer up to this

	 * point, use "default" policy entry