From bf4a80cbf1ec11260c1a458586f2433431646994 Mon Sep 17 00:00:00 2001 From: "Ahmed S. Darwish" Date: Sat, 25 Dec 2010 11:57:09 +0200 Subject: RAMOOPS: Don't overflow over non-allocated regions commit 1873bb8115e678ad9fd0aac9dbbc68383bc36e06 upstream. The current code mis-calculates the ramoops header size, leading to an overflow over the next record at best, or over a non-allocated region at worst. Fix that calculation. Signed-off-by: Ahmed S. Darwish Acked-by: Marco Stornelli Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen --- drivers/char/ramoops.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'drivers') diff --git a/drivers/char/ramoops.c b/drivers/char/ramoops.c index 74f00b5ffa36..9445f48c692f 100644 --- a/drivers/char/ramoops.c +++ b/drivers/char/ramoops.c @@ -27,7 +27,6 @@ #include #define RAMOOPS_KERNMSG_HDR "====" -#define RAMOOPS_HEADER_SIZE (5 + sizeof(struct timeval)) #define RECORD_SIZE 4096 @@ -63,8 +62,8 @@ static void ramoops_do_dump(struct kmsg_dumper *dumper, struct ramoops_context, dump); unsigned long s1_start, s2_start; unsigned long l1_cpy, l2_cpy; - int res; - char *buf; + int res, hdr_size; + char *buf, *buf_orig; struct timeval timestamp; /* Only dump oopses if dump_oops is set */ @@ -72,6 +71,8 @@ static void ramoops_do_dump(struct kmsg_dumper *dumper, return; buf = (char *)(cxt->virt_addr + (cxt->count * RECORD_SIZE)); + buf_orig = buf; + memset(buf, '\0', RECORD_SIZE); res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR); buf += res; @@ -79,8 +80,9 @@ static void ramoops_do_dump(struct kmsg_dumper *dumper, res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec); buf += res; - l2_cpy = min(l2, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_SIZE)); - l1_cpy = min(l1, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_SIZE) - l2_cpy); + hdr_size = buf - buf_orig; + l2_cpy = min(l2, (unsigned long)(RECORD_SIZE - hdr_size)); + l1_cpy = min(l1, (unsigned long)(RECORD_SIZE - hdr_size) - l2_cpy); s2_start = l2 - l2_cpy; s1_start = l1 - l1_cpy; -- cgit v1.2.3