diff options
| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2018-12-14 15:26:20 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-20 09:07:53 +0200 |
| commit | 14c328b46e23fcac4d9e2e38b989827e612e6d1e (patch) | |
| tree | 30ddb8a74acfbb2a74d600b0a6811dddc9533d20 /drivers/misc | |
| parent | 52796ff1a545a6fe5d4a5504ae14b871134d0f76 (diff) | |
| download | linux-rt-14c328b46e23fcac4d9e2e38b989827e612e6d1e.tar.gz | |
lkdtm: Add tests for NULL pointer dereference
[ Upstream commit 59a12205d3c32aee4c13ca36889fdf7cfed31126 ]
Introduce lkdtm tests for NULL pointer dereference: check access or exec
at NULL address, since these errors tend to be reported differently from
the general fault error text. For example from x86:
pr_alert("BUG: unable to handle kernel %s at %px\n",
address < PAGE_SIZE ? "NULL pointer dereference" : "paging request",
(void *)address);
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/lkdtm.h | 2 | ||||
| -rw-r--r-- | drivers/misc/lkdtm_core.c | 2 | ||||
| -rw-r--r-- | drivers/misc/lkdtm_perms.c | 18 |
3 files changed, 22 insertions, 0 deletions
diff --git a/drivers/misc/lkdtm.h b/drivers/misc/lkdtm.h index fdf954c2107f..6abc97b245e4 100644 --- a/drivers/misc/lkdtm.h +++ b/drivers/misc/lkdtm.h @@ -40,7 +40,9 @@ void lkdtm_EXEC_KMALLOC(void); void lkdtm_EXEC_VMALLOC(void); void lkdtm_EXEC_RODATA(void); void lkdtm_EXEC_USERSPACE(void); +void lkdtm_EXEC_NULL(void); void lkdtm_ACCESS_USERSPACE(void); +void lkdtm_ACCESS_NULL(void); /* lkdtm_rodata.c */ void lkdtm_rodata_do_nothing(void); diff --git a/drivers/misc/lkdtm_core.c b/drivers/misc/lkdtm_core.c index b2989f2d3126..035e51bea450 100644 --- a/drivers/misc/lkdtm_core.c +++ b/drivers/misc/lkdtm_core.c @@ -214,7 +214,9 @@ struct crashtype crashtypes[] = { CRASHTYPE(EXEC_VMALLOC), CRASHTYPE(EXEC_RODATA), CRASHTYPE(EXEC_USERSPACE), + CRASHTYPE(EXEC_NULL), CRASHTYPE(ACCESS_USERSPACE), + CRASHTYPE(ACCESS_NULL), CRASHTYPE(WRITE_RO), CRASHTYPE(WRITE_RO_AFTER_INIT), CRASHTYPE(WRITE_KERN), diff --git a/drivers/misc/lkdtm_perms.c b/drivers/misc/lkdtm_perms.c index 45f1c0f96612..1a9dcdaa95f0 100644 --- a/drivers/misc/lkdtm_perms.c +++ b/drivers/misc/lkdtm_perms.c @@ -160,6 +160,11 @@ void lkdtm_EXEC_USERSPACE(void) vm_munmap(user_addr, PAGE_SIZE); } +void lkdtm_EXEC_NULL(void) +{ + execute_location(NULL, CODE_AS_IS); +} + void lkdtm_ACCESS_USERSPACE(void) { unsigned long user_addr, tmp = 0; @@ -191,6 +196,19 @@ void lkdtm_ACCESS_USERSPACE(void) vm_munmap(user_addr, PAGE_SIZE); } +void lkdtm_ACCESS_NULL(void) +{ + unsigned long tmp; + unsigned long *ptr = (unsigned long *)NULL; + + pr_info("attempting bad read at %px\n", ptr); + tmp = *ptr; + tmp += 0xc0dec0de; + + pr_info("attempting bad write at %px\n", ptr); + *ptr = tmp; +} + void __init lkdtm_perms_init(void) { /* Make sure we can write to __ro_after_init values during __init */ |