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| author | Helge Deller <deller@gmx.de> | 2021-11-21 11:10:55 +0100 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2021-11-22 07:37:31 +0100 |
| commit | 98400ad75e95860e9a10ec78b0b90ab66184a2ce (patch) | |
| tree | 0b93bc1ce9a20537e60e0858c5ea760664581dfa /arch/parisc/kernel | |
| parent | parisc: Convert PTE lookup to use extru_safe() macro (diff) | |
| download | linux-98400ad75e95860e9a10ec78b0b90ab66184a2ce.tar.xz linux-98400ad75e95860e9a10ec78b0b90ab66184a2ce.zip | |
Revert "parisc: Fix backtrace to always include init funtion names"
This reverts commit 279917e27edc293eb645a25428c6ab3f3bca3f86.
With the CONFIG_HARDENED_USERCOPY option enabled, this patch triggers
kernel bugs at runtime:
usercopy: Kernel memory overwrite attempt detected to kernel text (offset 2084839, size 6)!
kernel BUG at mm/usercopy.c:99!
Backtrace:
IAOQ[0]: usercopy_abort+0xc4/0xe8
[<00000000406ed1c8>] __check_object_size+0x174/0x238
[<00000000407086d4>] copy_strings.isra.0+0x3e8/0x708
[<0000000040709a20>] do_execveat_common.isra.0+0x1bc/0x328
[<000000004070b760>] compat_sys_execve+0x7c/0xb8
[<0000000040303eb8>] syscall_exit+0x0/0x14
The problem is, that we have an init section of at least 2MB size which
starts at _stext and is freed after bootup.
If then later some kernel data is (temporarily) stored in this free
memory, check_kernel_text_object() will trigger a bug since the data
appears to be inside the kernel text (>=_stext) area:
if (overlaps(ptr, len, _stext, _etext))
usercopy_abort("kernel text");
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@kernel.org # 5.4+
Diffstat (limited to 'arch/parisc/kernel')
| -rw-r--r-- | arch/parisc/kernel/vmlinux.lds.S | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/parisc/kernel/vmlinux.lds.S b/arch/parisc/kernel/vmlinux.lds.S index 3d208afd15bc..2769eb991f58 100644 --- a/arch/parisc/kernel/vmlinux.lds.S +++ b/arch/parisc/kernel/vmlinux.lds.S @@ -57,8 +57,6 @@ SECTIONS { . = KERNEL_BINARY_TEXT_START; - _stext = .; /* start of kernel text, includes init code & data */ - __init_begin = .; HEAD_TEXT_SECTION MLONGCALL_DISCARD(INIT_TEXT_SECTION(8)) @@ -82,6 +80,7 @@ SECTIONS /* freed after init ends here */ _text = .; /* Text and read-only data */ + _stext = .; MLONGCALL_KEEP(INIT_TEXT_SECTION(8)) .text ALIGN(PAGE_SIZE) : { TEXT_TEXT |