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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-17 20:47:50 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-17 20:47:50 (GMT) |
commit | 8eee93e2576c303b6071368456dcd6c9a5a021c9 (patch) | |
tree | 0c65d2dc160af900e0c87ebc4b41979c0b9075cf /drivers/misc/lkdtm.c | |
parent | 1a4ab084afaa8e5405a3e22aca21478ee3ca5d59 (diff) | |
parent | 16617535684faf9de30620de83667214297a36b8 (diff) | |
download | linux-8eee93e2576c303b6071368456dcd6c9a5a021c9.tar.xz |
Merge tag 'char-misc-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc updates from Greg KH:
"Here is the big char/misc driver update for 4.6-rc1.
The majority of the patches here is hwtracing and some new mic
drivers, but there's a lot of other driver updates as well. Full
details in the shortlog.
All have been in linux-next for a while with no reported issues"
* tag 'char-misc-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (238 commits)
goldfish: Fix build error of missing ioremap on UM
nvmem: mediatek: Fix later provider initialization
nvmem: imx-ocotp: Fix return value of imx_ocotp_read
nvmem: Fix dependencies for !HAS_IOMEM archs
char: genrtc: replace blacklist with whitelist
drivers/hwtracing: make coresight-etm-perf.c explicitly non-modular
drivers: char: mem: fix IS_ERROR_VALUE usage
char: xillybus: Fix internal data structure initialization
pch_phub: return -ENODATA if ROM can't be mapped
Drivers: hv: vmbus: Support kexec on ws2012 r2 and above
Drivers: hv: vmbus: Support handling messages on multiple CPUs
Drivers: hv: utils: Remove util transport handler from list if registration fails
Drivers: hv: util: Pass the channel information during the init call
Drivers: hv: vmbus: avoid unneeded compiler optimizations in vmbus_wait_for_unload()
Drivers: hv: vmbus: remove code duplication in message handling
Drivers: hv: vmbus: avoid wait_for_completion() on crash
Drivers: hv: vmbus: don't loose HVMSG_TIMER_EXPIRED messages
misc: at24: replace memory_accessor with nvmem_device_read
eeprom: 93xx46: extend driver to plug into the NVMEM framework
eeprom: at25: extend driver to plug into the NVMEM framework
...
Diffstat (limited to 'drivers/misc/lkdtm.c')
-rw-r--r-- | drivers/misc/lkdtm.c | 124 |
1 files changed, 120 insertions, 4 deletions
diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c index 2a6eaf1..5f1a36b 100644 --- a/drivers/misc/lkdtm.c +++ b/drivers/misc/lkdtm.c @@ -92,6 +92,9 @@ enum ctype { CT_UNALIGNED_LOAD_STORE_WRITE, CT_OVERWRITE_ALLOCATION, CT_WRITE_AFTER_FREE, + CT_READ_AFTER_FREE, + CT_WRITE_BUDDY_AFTER_FREE, + CT_READ_BUDDY_AFTER_FREE, CT_SOFTLOCKUP, CT_HARDLOCKUP, CT_SPINLOCKUP, @@ -105,6 +108,7 @@ enum ctype { CT_WRITE_RO, CT_WRITE_RO_AFTER_INIT, CT_WRITE_KERN, + CT_WRAP_ATOMIC }; static char* cp_name[] = { @@ -130,6 +134,9 @@ static char* cp_type[] = { "UNALIGNED_LOAD_STORE_WRITE", "OVERWRITE_ALLOCATION", "WRITE_AFTER_FREE", + "READ_AFTER_FREE", + "WRITE_BUDDY_AFTER_FREE", + "READ_BUDDY_AFTER_FREE", "SOFTLOCKUP", "HARDLOCKUP", "SPINLOCKUP", @@ -143,6 +150,7 @@ static char* cp_type[] = { "WRITE_RO", "WRITE_RO_AFTER_INIT", "WRITE_KERN", + "WRAP_ATOMIC" }; static struct jprobe lkdtm; @@ -338,7 +346,7 @@ static noinline void corrupt_stack(void) memset((void *)data, 0, 64); } -static void execute_location(void *dst) +static void noinline execute_location(void *dst) { void (*func)(void) = dst; @@ -412,12 +420,109 @@ static void lkdtm_do_action(enum ctype which) break; } case CT_WRITE_AFTER_FREE: { + int *base, *again; size_t len = 1024; - u32 *data = kmalloc(len, GFP_KERNEL); + /* + * The slub allocator uses the first word to store the free + * pointer in some configurations. Use the middle of the + * allocation to avoid running into the freelist + */ + size_t offset = (len / sizeof(*base)) / 2; + + base = kmalloc(len, GFP_KERNEL); + pr_info("Allocated memory %p-%p\n", base, &base[offset * 2]); + pr_info("Attempting bad write to freed memory at %p\n", + &base[offset]); + kfree(base); + base[offset] = 0x0abcdef0; + /* Attempt to notice the overwrite. */ + again = kmalloc(len, GFP_KERNEL); + kfree(again); + if (again != base) + pr_info("Hmm, didn't get the same memory range.\n"); - kfree(data); + break; + } + case CT_READ_AFTER_FREE: { + int *base, *val, saw; + size_t len = 1024; + /* + * The slub allocator uses the first word to store the free + * pointer in some configurations. Use the middle of the + * allocation to avoid running into the freelist + */ + size_t offset = (len / sizeof(*base)) / 2; + + base = kmalloc(len, GFP_KERNEL); + if (!base) + break; + + val = kmalloc(len, GFP_KERNEL); + if (!val) + break; + + *val = 0x12345678; + base[offset] = *val; + pr_info("Value in memory before free: %x\n", base[offset]); + + kfree(base); + + pr_info("Attempting bad read from freed memory\n"); + saw = base[offset]; + if (saw != *val) { + /* Good! Poisoning happened, so declare a win. */ + pr_info("Memory correctly poisoned (%x)\n", saw); + BUG(); + } + pr_info("Memory was not poisoned\n"); + + kfree(val); + break; + } + case CT_WRITE_BUDDY_AFTER_FREE: { + unsigned long p = __get_free_page(GFP_KERNEL); + if (!p) + break; + pr_info("Writing to the buddy page before free\n"); + memset((void *)p, 0x3, PAGE_SIZE); + free_page(p); schedule(); - memset(data, 0x78, len); + pr_info("Attempting bad write to the buddy page after free\n"); + memset((void *)p, 0x78, PAGE_SIZE); + /* Attempt to notice the overwrite. */ + p = __get_free_page(GFP_KERNEL); + free_page(p); + schedule(); + + break; + } + case CT_READ_BUDDY_AFTER_FREE: { + unsigned long p = __get_free_page(GFP_KERNEL); + int saw, *val = kmalloc(1024, GFP_KERNEL); + int *base; + + if (!p) + break; + + if (!val) + break; + + base = (int *)p; + + *val = 0x12345678; + base[0] = *val; + pr_info("Value in memory before free: %x\n", base[0]); + free_page(p); + pr_info("Attempting to read from freed memory\n"); + saw = base[0]; + if (saw != *val) { + /* Good! Poisoning happened, so declare a win. */ + pr_info("Memory correctly poisoned (%x)\n", saw); + BUG(); + } + pr_info("Buddy page was not poisoned\n"); + + kfree(val); break; } case CT_SOFTLOCKUP: @@ -548,6 +653,17 @@ static void lkdtm_do_action(enum ctype which) do_overwritten(); break; } + case CT_WRAP_ATOMIC: { + atomic_t under = ATOMIC_INIT(INT_MIN); + atomic_t over = ATOMIC_INIT(INT_MAX); + + pr_info("attempting atomic underflow\n"); + atomic_dec(&under); + pr_info("attempting atomic overflow\n"); + atomic_inc(&over); + + return; + } case CT_NONE: default: break; |