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| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-24 20:30:04 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-24 20:30:04 +0200 |
| commit | 02bd610e858d764fb32ebfa123083fdbadd88a08 (patch) | |
| tree | 468f5319ab0dc0ef517b1adaedf7866b578ce88d /drivers/misc/lkdtm/usercopy.c | |
| parent | 6660a04feb7ef648e50c792e19084d675fa6f3a2 (diff) | |
| parent | 24cccab42c4199c6daa0a6981e6f6a1ffb0b5a09 (diff) | |
| download | linux-02bd610e858d764fb32ebfa123083fdbadd88a08.tar.gz linux-02bd610e858d764fb32ebfa123083fdbadd88a08.tar.bz2 linux-02bd610e858d764fb32ebfa123083fdbadd88a08.zip | |
Merge tag 'lkdtm-next' of https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux into char-misc-linus
Kees writes:
lkdtm: various fixes
- Move KERNEL_DS test to non-canonical range
- Make stack exhaustion test more robust
* tag 'lkdtm-next' of https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
lkdtm/bugs: Adjust recursion test to avoid elision
lkdtm/usercopy: Moves the KERNEL_DS test to non-canonical
Diffstat (limited to 'drivers/misc/lkdtm/usercopy.c')
| -rw-r--r-- | drivers/misc/lkdtm/usercopy.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/misc/lkdtm/usercopy.c b/drivers/misc/lkdtm/usercopy.c index d5a0e7f1813b..e172719dd86d 100644 --- a/drivers/misc/lkdtm/usercopy.c +++ b/drivers/misc/lkdtm/usercopy.c @@ -324,14 +324,16 @@ free_user: void lkdtm_USERCOPY_KERNEL_DS(void) { - char __user *user_ptr = (char __user *)ERR_PTR(-EINVAL); + char __user *user_ptr = + (char __user *)(0xFUL << (sizeof(unsigned long) * 8 - 4)); mm_segment_t old_fs = get_fs(); char buf[10] = {0}; - pr_info("attempting copy_to_user on unmapped kernel address\n"); + pr_info("attempting copy_to_user() to noncanonical address: %px\n", + user_ptr); set_fs(KERNEL_DS); - if (copy_to_user(user_ptr, buf, sizeof(buf))) - pr_info("copy_to_user un unmapped kernel address failed\n"); + if (copy_to_user(user_ptr, buf, sizeof(buf)) == 0) + pr_err("copy_to_user() to noncanonical address succeeded!?\n"); set_fs(old_fs); } |