From: Greg Kroah-Hartman Date: Sun, 14 Feb 2021 17:16:43 +0000 (+0100) Subject: 5.10-stable patches X-Git-Tag: v5.4.99~36 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=528c3038f4c7688c50a59cd64df2f3c26785f947;p=thirdparty%2Fkernel%2Fstable-queue.git 5.10-stable patches added patches: lkdtm-don-t-move-ctors-to-.rodata.patch --- diff --git a/queue-5.10/lkdtm-don-t-move-ctors-to-.rodata.patch b/queue-5.10/lkdtm-don-t-move-ctors-to-.rodata.patch new file mode 100644 index 00000000000..21fe8dada96 --- /dev/null +++ b/queue-5.10/lkdtm-don-t-move-ctors-to-.rodata.patch @@ -0,0 +1,100 @@ +From 3f618ab3323407ee4c6a6734a37eb6e9663ebfb9 Mon Sep 17 00:00:00 2001 +From: Mark Rutland +Date: Mon, 7 Dec 2020 17:05:33 +0000 +Subject: lkdtm: don't move ctors to .rodata + +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 +Cc: Stephen Boyd +Signed-off-by: Greg Kroah-Hartman +--- + drivers/misc/lkdtm/Makefile | 2 +- + drivers/misc/lkdtm/rodata.c | 2 +- + 2 files changed, 2 insertions(+), 2 deletions(-) + +--- a/drivers/misc/lkdtm/Makefile ++++ b/drivers/misc/lkdtm/Makefile +@@ -16,7 +16,7 @@ KCOV_INSTRUMENT_rodata.o := n + + OBJCOPYFLAGS := + OBJCOPYFLAGS_rodata_objcopy.o := \ +- --rename-section .text=.rodata,alloc,readonly,load ++ --rename-section .noinstr.text=.rodata,alloc,readonly,load + targets += rodata.o rodata_objcopy.o + $(obj)/rodata_objcopy.o: $(obj)/rodata.o FORCE + $(call if_changed,objcopy) +--- a/drivers/misc/lkdtm/rodata.c ++++ b/drivers/misc/lkdtm/rodata.c +@@ -5,7 +5,7 @@ + */ + #include "lkdtm.h" + +-void notrace lkdtm_rodata_do_nothing(void) ++void noinstr lkdtm_rodata_do_nothing(void) + { + /* Does nothing. We just want an architecture agnostic "return". */ + } diff --git a/queue-5.10/series b/queue-5.10/series index bae5c99e88c..a243bc71b82 100644 --- a/queue-5.10/series +++ b/queue-5.10/series @@ -44,3 +44,4 @@ kasan-add-explicit-preconditions-to-kasan_report.patch ubsan-implement-__ubsan_handle_alignment_assumption.patch revert-lib-restrict-cpumask_local_spread-to-houskeep.patch x86-efi-remove-efi-pgd-build-time-checks.patch +lkdtm-don-t-move-ctors-to-.rodata.patch