Patch "bpf, arm64: Fix trampoline for BPF_TRAMP_F_CALL_ORIG" has been added to the 6.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    bpf, arm64: Fix trampoline for BPF_TRAMP_F_CALL_ORIG

to the 6.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     bpf-arm64-fix-trampoline-for-bpf_tramp_f_call_orig.patch
and it can be found in the queue-6.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 62e8353dcca454ba49f15805be1d53d0eccd86b4
Author: Puranjay Mohan <puranjay@xxxxxxxxxx>
Date:   Thu Jul 11 15:18:38 2024 +0000

    bpf, arm64: Fix trampoline for BPF_TRAMP_F_CALL_ORIG
    
    [ Upstream commit 19d3c179a37730caf600a97fed3794feac2b197b ]
    
    When BPF_TRAMP_F_CALL_ORIG is set, the trampoline calls
    __bpf_tramp_enter() and __bpf_tramp_exit() functions, passing them
    the struct bpf_tramp_image *im pointer as an argument in R0.
    
    The trampoline generation code uses emit_addr_mov_i64() to emit
    instructions for moving the bpf_tramp_image address into R0, but
    emit_addr_mov_i64() assumes the address to be in the vmalloc() space
    and uses only 48 bits. Because bpf_tramp_image is allocated using
    kzalloc(), its address can use more than 48-bits, in this case the
    trampoline will pass an invalid address to __bpf_tramp_enter/exit()
    causing a kernel crash.
    
    Fix this by using emit_a64_mov_i64() in place of emit_addr_mov_i64()
    as it can work with addresses that are greater than 48-bits.
    
    Fixes: efc9909fdce0 ("bpf, arm64: Add bpf trampoline for arm64")
    Signed-off-by: Puranjay Mohan <puranjay@xxxxxxxxxx>
    Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
    Closes: https://lore.kernel.org/all/SJ0PR15MB461564D3F7E7A763498CA6A8CBDB2@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
    Link: https://lore.kernel.org/bpf/20240711151838.43469-1-puranjay@xxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 720336d288568..1bf483ec971d9 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -2141,7 +2141,7 @@ static int prepare_trampoline(struct jit_ctx *ctx, struct bpf_tramp_image *im,
 	emit(A64_STR64I(A64_R(20), A64_SP, regs_off + 8), ctx);
 
 	if (flags & BPF_TRAMP_F_CALL_ORIG) {
-		emit_addr_mov_i64(A64_R(0), (const u64)im, ctx);
+		emit_a64_mov_i64(A64_R(0), (const u64)im, ctx);
 		emit_call((const u64)__bpf_tramp_enter, ctx);
 	}
 
@@ -2185,7 +2185,7 @@ static int prepare_trampoline(struct jit_ctx *ctx, struct bpf_tramp_image *im,
 
 	if (flags & BPF_TRAMP_F_CALL_ORIG) {
 		im->ip_epilogue = ctx->ro_image + ctx->idx;
-		emit_addr_mov_i64(A64_R(0), (const u64)im, ctx);
+		emit_a64_mov_i64(A64_R(0), (const u64)im, ctx);
 		emit_call((const u64)__bpf_tramp_exit, ctx);
 	}