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Commit e7eb8726 authored by Cliff Wickman's avatar Cliff Wickman Committed by Ingo Molnar
Browse files

x86, SGI UV: uv_ptc_proc_write fix 



Someone could write 0 bytes to /proc/sgi_uv/ptc_statistics,
causing
  optstr[count - 1] = '\0';
to write to who-knows-where.

(Andi Kleen noticed this need from a patch I sent for
 similar code in the ia64 world (sn2_ptc_proc_write()).)

(count less than zero is not possible here, as count is unsigned)

Signed-off-by: default avatarCliff Wickman <cpw@sgi.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent cef53278

arch/x86/kernel/tlb_uv.c

+1 −1
Original line number Diff line number Diff line
@@ -492,7 +492,7 @@ static ssize_t uv_ptc_proc_write(struct file *file, const char __user *user, 
	long newmode;

	char optstr[64];



	if (count > 64)

	if (count == 0 || count > sizeof(optstr))

		return -EINVAL;

	if (copy_from_user(optstr, user, count))

		return -EFAULT;