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| author | Mark Brown <broonie@kernel.org> | 2019-06-10 18:52:53 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2019-06-10 18:52:53 +0100 |
| commit | 4343f61103cdb8ccd6f3d5dd7168f1176a1cee37 (patch) | |
| tree | 3db0a2e099cf7feb0c2d60d2a4bf1bf10d5253db /drivers/misc/lkdtm/usercopy.c | |
| parent | aef9752274f4045b0dab577e113da63c96832f77 (diff) | |
| parent | d1fdb6d8f6a4109a4263176c84b899076a5f8008 (diff) | |
Merge tag 'v5.2-rc4' into spi-5.3
Linux 5.2-rc4
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); } |