diff options
| author | Ahmed S. Darwish <darwish.07@gmail.com> | 2010-12-25 11:57:09 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-01-07 13:58:42 -0800 |
| commit | 8a228e5dcd2e464a974a06b4460f124afbe80ad3 (patch) | |
| tree | dc48587d3fc6f4c2c0dd0ba1a35c8698800e819b /drivers/char | |
| parent | 879ef03a76c5169898a121e988f3eaaabb95d73a (diff) | |
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 <darwish.07@gmail.com>
Acked-by: Marco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/ramoops.c | 12 |
1 files changed, 7 insertions, 5 deletions
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 <linux/ioport.h> #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; |