From: Youling Tang tangyouling@kylinos.cn

Automatically disable kaslr when the kernel loads from kexec_file.

kexec_file loads the secondary kernel image to a non-linked address, inherently providing KASLR-like randomization.

However, on LoongArch where System RAM may be non-contiguous, enabling KASLR for the second kernel could relocate it to an invalid memory region and cause boot failure. Thus, we disable KASLR when "kexec_file" is detected in the command line.

To ensure compatibility with older kernels loaded via kexec_file, this patch need be backported to stable branches.

Cc: stable@vger.kernel.org Signed-off-by: Youling Tang tangyouling@kylinos.cn --- arch/loongarch/kernel/relocate.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/arch/loongarch/kernel/relocate.c b/arch/loongarch/kernel/relocate.c index 50c469067f3a..4c097532cb88 100644 --- a/arch/loongarch/kernel/relocate.c +++ b/arch/loongarch/kernel/relocate.c @@ -140,6 +140,10 @@ static inline __init bool kaslr_disabled(void) if (str == boot_command_line || (str > boot_command_line && *(str - 1) == ' ')) return true;

+ str = strstr(boot_command_line, "kexec_file"); + if (str == boot_command_line || (str > boot_command_line && *(str - 1) == ' ')) + return true; + #ifdef CONFIG_HIBERNATION str = strstr(builtin_cmdline, "nohibernate"); if (str == builtin_cmdline || (str > builtin_cmdline && *(str - 1) == ' '))