kernel/linux.git/drivers/misc/lkdtm, branch v4.19.112

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