The patch titled
/dev/mem: dont allow seek to last page
has been added to the -mm tree. Its filename is
devmem-dont-allow-seek-to-last-page.patch
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------------------------------------------------------
Subject: /dev/mem: dont allow seek to last page
From: Wu Fengguang <fengguang.wu@xxxxxxxxx>
So as to return a uniform error -EOVERFLOW instead of a random one:
# kmem-seek 0xfffffffffffffff0
seek /dev/kmem: Device or resource busy
# kmem-seek 0xfffffffffffffff1
seek /dev/kmem: Block device required
Suggested by OGAWA Hirofumi.
Cc: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/char/mem.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff -puN drivers/char/mem.c~devmem-dont-allow-seek-to-last-page drivers/char/mem.c
--- a/drivers/char/mem.c~devmem-dont-allow-seek-to-last-page
+++ a/drivers/char/mem.c
@@ -708,16 +708,23 @@ static loff_t memory_lseek(struct file *
mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
switch (orig) {
- case 0:
+ case SEEK_CUR:
+ offset += file->f_pos;
+ if ((unsigned long long)offset <
+ (unsigned long long)file->f_pos) {
+ ret = -EOVERFLOW;
+ break;
+ }
+ case SEEK_SET:
+ /* to avoid userland mistaking f_pos=-9 as -EBADF=-9 */
+ if ((unsigned long long)offset >= ~0xFFFULL) {
+ ret = -EOVERFLOW;
+ break;
+ }
file->f_pos = offset;
ret = file->f_pos;
force_successful_syscall_return();
break;
- case 1:
- file->f_pos += offset;
- ret = file->f_pos;
- force_successful_syscall_return();
- break;
default:
ret = -EINVAL;
}
_
Patches currently in -mm which might be from fengguang.wu@xxxxxxxxx are
linux-next.patch
fanotify-fix-fmode_nonotify-bit-number.patch
vfs-improve-writeback_inodes_wb.patch
vfs-o_-bit-numbers-uniqueness-check.patch
vfs-introduce-fmode_neg_offset-for-allowing-negative-f_pos.patch
mm-introduce-dump_page-and-print-symbolic-flag-names.patch
vmscan-check-high-watermark-after-shrink-zone.patch
vmscan-check-high-watermark-after-shrink-zone-fix.patch
mm-restore-zone-all_unreclaimable-to-independence-word.patch
mm-restore-zone-all_unreclaimable-to-independence-word-fix.patch
mm-restore-zone-all_unreclaimable-to-independence-word-fix-2.patch
memory-hotplug-create-sys-firmware-memmap-entry-for-new-memory.patch
memory-hotplug-create-sys-firmware-memmap-entry-for-new-memory-fix.patch
vfs-take-f_lock-on-modifying-f_mode-after-open-time.patch
readahead-introduce-fmode_random-for-posix_fadv_random.patch
readahead-introduce-fmode_random-for-posix_fadv_random-fix.patch
include-linux-fsh-convert-fmode_-constants-to-hex.patch
devmem-dont-allow-seek-to-last-page.patch
vfs-add-super-operation-writeback_inodes.patch
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