From 5134fc15b643dc36eb9aa77e4318b886844a9ac5 Mon Sep 17 00:00:00 2001 From: Paul Jackson Date: Wed, 28 Sep 2005 06:42:24 -0700 Subject: [PATCH] [PATCH] cpuset read past eof memory leak fix Don't leak a page of memory if user reads a cpuset file past eof. Signed-off-by: KUROSAWA Takahiro Signed-off-by: Paul Jackson Signed-off-by: Linus Torvalds --- kernel/cpuset.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 79866bc6b3a1..6a6e87b2f2fd 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -969,7 +969,7 @@ static ssize_t cpuset_common_file_read(struct file *file, char __user *buf, ssize_t retval = 0; char *s; char *start; - size_t n; + ssize_t n; if (!(page = (char *)__get_free_page(GFP_KERNEL))) return -ENOMEM; @@ -999,12 +999,13 @@ static ssize_t cpuset_common_file_read(struct file *file, char __user *buf, *s++ = '\n'; *s = '\0'; - /* Do nothing if *ppos is at the eof or beyond the eof. */ - if (s - page <= *ppos) - return 0; - start = page + *ppos; n = s - start; + + /* Do nothing if *ppos is at the eof or beyond the eof. */ + if (n <= 0) + goto out; + retval = n - copy_to_user(buf, start, min(n, nbytes)); *ppos += retval; out: -- 2.20.1