kernel/git/stable/linux-stable.git/drivers/misc/lkdtm, branch linux-4.19.y

lkdtm/usercopy: Expand size of "out of frame" object

2022-06-14T14:59:36+00:00

[ Upstream commit f387e86d3a74407bdd9c5815820ac9d060962840 ] To be sufficiently out of range for the usercopy test to see the lifetime mismatch, expand the size of the "bad" buffer, which will let it be beyond current_stack_pointer regardless of stack growth direction. Paired with the recent addition of stack depth checking under CONFIG_HARDENED_USERCOPY=y, this will correctly start tripping again. Reported-by: Muhammad Usama Anjum Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Reviewed-by: Muhammad Usama Anjum Link: https://lore.kernel.org/lkml/762faf1b-0443-5ddf-4430-44a20cf2ec4d@collabora.com/ Signed-off-by: Kees Cook Signed-off-by: Sasha Levin

lkdtm: Fix content of section containing lkdtm_rodata_do_nothing()

2022-01-27T08:04:16+00:00

commit bc93a22a19eb2b68a16ecf04cdf4b2ed65aaf398 upstream. On a kernel without CONFIG_STRICT_KERNEL_RWX, running EXEC_RODATA test leads to "Illegal instruction" failure. Looking at the content of rodata_objcopy.o, we see that the function content zeroes only: Disassembly of section .rodata: 0000000000000000 <.lkdtm_rodata_do_nothing>: 0: 00 00 00 00 .long 0x0 Add the contents flag in order to keep the content of the section while renaming it. Disassembly of section .rodata: 0000000000000000 <.lkdtm_rodata_do_nothing>: 0: 4e 80 00 20 blr Fixes: e9e08a07385e ("lkdtm: support llvm-objcopy") Cc: stable@vger.kernel.org Cc: Kees Cook Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Nick Desaulniers Cc: Nathan Chancellor Signed-off-by: Christophe Leroy Reviewed-by: Nick Desaulniers Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/8900731fbc05fb8b0de18af7133a8fc07c3c53a1.1633712176.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman

lkdtm: don't move ctors to .rodata

2021-03-24T10:07:31+00:00

From: Mark Rutland commit 3f618ab3323407ee4c6a6734a37eb6e9663ebfb9 upstream. When building with KASAN and LKDTM, clang may implictly generate an asan.module_ctor function in the LKDTM rodata object. The Makefile moves the lkdtm_rodata_do_nothing() function into .rodata by renaming the file's .text section to .rodata, and consequently also moves the ctor function into .rodata, leading to a boot time crash (splat below) when the ctor is invoked by do_ctors(). Let's prevent this by marking the function as noinstr rather than notrace, and renaming the file's .noinstr.text to .rodata. Marking the function as noinstr will prevent tracing and kprobes, and will inhibit any undesireable compiler instrumentation. The ctor function (if any) will be placed in .text and will work correctly. Example splat before this patch is applied: [ 0.916359] Unable to handle kernel execute from non-executable memory at virtual address ffffa0006b60f5ac [ 0.922088] Mem abort info: [ 0.922828] ESR = 0x8600000e [ 0.923635] EC = 0x21: IABT (current EL), IL = 32 bits [ 0.925036] SET = 0, FnV = 0 [ 0.925838] EA = 0, S1PTW = 0 [ 0.926714] swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000000427b3000 [ 0.928489] [ffffa0006b60f5ac] pgd=000000023ffff003, p4d=000000023ffff003, pud=000000023fffe003, pmd=0068000042000f01 [ 0.931330] Internal error: Oops: 8600000e [#1] PREEMPT SMP [ 0.932806] Modules linked in: [ 0.933617] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.10.0-rc7 #2 [ 0.935620] Hardware name: linux,dummy-virt (DT) [ 0.936924] pstate: 40400005 (nZcv daif +PAN -UAO -TCO BTYPE=--) [ 0.938609] pc : asan.module_ctor+0x0/0x14 [ 0.939759] lr : do_basic_setup+0x4c/0x70 [ 0.940889] sp : ffff27b600177e30 [ 0.941815] x29: ffff27b600177e30 x28: 0000000000000000 [ 0.943306] x27: 0000000000000000 x26: 0000000000000000 [ 0.944803] x25: 0000000000000000 x24: 0000000000000000 [ 0.946289] x23: 0000000000000001 x22: 0000000000000000 [ 0.947777] x21: ffffa0006bf4a890 x20: ffffa0006befb6c0 [ 0.949271] x19: ffffa0006bef9358 x18: 0000000000000068 [ 0.950756] x17: fffffffffffffff8 x16: 0000000000000000 [ 0.952246] x15: 0000000000000000 x14: 0000000000000000 [ 0.953734] x13: 00000000838a16d5 x12: 0000000000000001 [ 0.955223] x11: ffff94000da74041 x10: dfffa00000000000 [ 0.956715] x9 : 0000000000000000 x8 : ffffa0006b60f5ac [ 0.958199] x7 : f9f9f9f9f9f9f9f9 x6 : 000000000000003f [ 0.959683] x5 : 0000000000000040 x4 : 0000000000000000 [ 0.961178] x3 : ffffa0006bdc15a0 x2 : 0000000000000005 [ 0.962662] x1 : 00000000000000f9 x0 : ffffa0006bef9350 [ 0.964155] Call trace: [ 0.964844] asan.module_ctor+0x0/0x14 [ 0.965895] kernel_init_freeable+0x158/0x198 [ 0.967115] kernel_init+0x14/0x19c [ 0.968104] ret_from_fork+0x10/0x30 [ 0.969110] Code: 00000003 00000000 00000000 00000000 (00000000) [ 0.970815] ---[ end trace b5339784e20d015c ]--- Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Kees Cook Acked-by: Kees Cook Signed-off-by: Mark Rutland Link: https://lore.kernel.org/r/20201207170533.10738-1-mark.rutland@arm.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Nicolas Boichat Signed-off-by: Greg Kroah-Hartman

lkdtm: support llvm-objcopy

2019-07-14T06:11:21+00:00

commit e9e08a07385e08f1a7f85c5d1e345c21c9564963 upstream. With CONFIG_LKDTM=y and make OBJCOPY=llvm-objcopy, llvm-objcopy errors: llvm-objcopy: error: --set-section-flags=.text conflicts with --rename-section=.text=.rodata Rather than support setting flags then renaming sections vs renaming then setting flags, it's simpler to just change both at the same time via --rename-section. Adding the load flag is required for GNU objcopy to mark .rodata Type as PROGBITS after the rename. This can be verified with: $ readelf -S drivers/misc/lkdtm/rodata_objcopy.o ... Section Headers: [Nr] Name Type Address Offset Size EntSize Flags Link Info Align ... [ 1] .rodata PROGBITS 0000000000000000 00000040 0000000000000004 0000000000000000 A 0 0 4 ... Which shows that .text is now renamed .rodata, the alloc flag A is set, the type is PROGBITS, and the section is not flagged as writeable W. Cc: stable@vger.kernel.org Link: https://sourceware.org/bugzilla/show_bug.cgi?id=24554 Link: https://github.com/ClangBuiltLinux/linux/issues/448 Reported-by: Nathan Chancellor Suggested-by: Alan Modra Suggested-by: Jordan Rupprect Suggested-by: Kees Cook Acked-by: Kees Cook Reviewed-by: Nathan Chancellor Signed-off-by: Nick Desaulniers Signed-off-by: Greg Kroah-Hartman

lkdtm: Add tests for NULL pointer dereference

2019-04-20T07:16:04+00:00

[ 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 Signed-off-by: Kees Cook Signed-off-by: Sasha Levin

lkdtm: Print real addresses

2019-04-20T07:16:03+00:00

[ Upstream commit 4c411157a42f122051ae3469bee0b5cabe89e139 ] Today, when doing a lkdtm test before the readiness of the random generator, (ptrval) is printed instead of the address at which it perform the fault: [ 1597.337030] lkdtm: Performing direct entry EXEC_USERSPACE [ 1597.337142] lkdtm: attempting ok execution at (ptrval) [ 1597.337398] lkdtm: attempting bad execution at (ptrval) [ 1597.337460] kernel tried to execute user page (77858000) -exploit attempt? (uid: 0) [ 1597.344769] Unable to handle kernel paging request for instruction fetch [ 1597.351392] Faulting instruction address: 0x77858000 [ 1597.356312] Oops: Kernel access of bad area, sig: 11 [#1] If the lkdtm test is done later on, it prints an hashed address. In both cases this is pointless. The purpose of the test is to ensure the kernel generates an Oops at the expected address, so real addresses needs to be printed. This patch fixes that. Signed-off-by: Christophe Leroy Signed-off-by: Kees Cook Signed-off-by: Sasha Levin

lkdtm: Add missing SPDX-License-Identifier line

2018-03-07T03:18:55+00:00

The refcount.c file missed the mass-addition of the SPDX lines. Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

lkdtm: Relocate code to subdirectory

2018-03-07T03:18:55+00:00

The LKDTM modules keep expanding, and it's getting weird to have each file get a prefix. Instead, move to a subdirectory for cleaner handling. Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman