The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 13134cc949148e1dfa540a0fe5dc73569bc62155 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025011231-bakery-sterling-1f23@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 13134cc949148e1dfa540a0fe5dc73569bc62155 Mon Sep 17 00:00:00 2001 From: Nam Cao namcao@linutronix.de Date: Tue, 19 Nov 2024 12:10:56 +0100 Subject: [PATCH] riscv: kprobes: Fix incorrect address calculation

p->ainsn.api.insn is a pointer to u32, therefore arithmetic operations are multiplied by four. This is clearly undesirable for this case.

Cast it to (void *) first before any calculation.

Below is a sample before/after. The dumped memory is two kprobe slots, the first slot has

- c.addiw a0, 0x1c (0x7125) - ebreak (0x00100073)

and the second slot has:

- c.addiw a0, -4 (0x7135) - ebreak (0x00100073)

Before this patch:

(gdb) x/16xh 0xff20000000135000 0xff20000000135000: 0x7125 0x0000 0x0000 0x0000 0x7135 0x0010 0x0000 0x0000 0xff20000000135010: 0x0073 0x0010 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000

After this patch:

(gdb) x/16xh 0xff20000000125000 0xff20000000125000: 0x7125 0x0073 0x0010 0x0000 0x7135 0x0073 0x0010 0x0000 0xff20000000125010: 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000

Fixes: b1756750a397 ("riscv: kprobes: Use patch_text_nosync() for insn slots") Signed-off-by: Nam Cao namcao@linutronix.de Cc: stable@vger.kernel.org Reviewed-by: Alexandre Ghiti alexghiti@rivosinc.com Link: https://lore.kernel.org/r/20241119111056.2554419-1-namcao@linutronix.de Signed-off-by: Palmer Dabbelt palmer@rivosinc.com

diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c index 380a0e8cecc0..c0738d6c6498 100644 --- a/arch/riscv/kernel/probes/kprobes.c +++ b/arch/riscv/kernel/probes/kprobes.c @@ -30,7 +30,7 @@ static void __kprobes arch_prepare_ss_slot(struct kprobe *p) p->ainsn.api.restore = (unsigned long)p->addr + len;

patch_text_nosync(p->ainsn.api.insn, &p->opcode, len); - patch_text_nosync(p->ainsn.api.insn + len, &insn, GET_INSN_LENGTH(insn)); + patch_text_nosync((void *)p->ainsn.api.insn + len, &insn, GET_INSN_LENGTH(insn)); }

static void __kprobes arch_prepare_simulate(struct kprobe *p)