tree e4b7b50d915495703994d10268c876069701d5c2
parent 8cd3901cf609e4dd5ef16035248f86cf446dbd55
author Puranjay Mohan <puranjay@kernel.org> 1720711118 +0000
committer He Gao <hegao@google.com> 1748648996 -0700

bpf, arm64: Fix trampoline for BPF_TRAMP_F_CALL_ORIG

commit 19d3c179a37730caf600a97fed3794feac2b197b upstream.

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.

BUG=b/376425754
TEST=presubmit
RELEASE_NOTE=Fixed CVE-2024-43840 in the Linux kernel.

cos-patch: security-moderate
Fixes: efc9909fdce0 ("bpf, arm64: Add bpf trampoline for arm64")
Change-Id: I26661b285d72dde5a1a317f977256b26217c13c7
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Closes: https://lore.kernel.org/all/SJ0PR15MB461564D3F7E7A763498CA6A8CBDB2@SJ0PR15MB4615.namprd15.prod.outlook.com/
Link: https://lore.kernel.org/bpf/20240711151838.43469-1-puranjay@kernel.org
[Minor context change fixed.]
Signed-off-by: Bin Lan <bin.lan.cn@windriver.com>
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kernel CVE Triage Automation <cloud-image-kernel-cve-triage-automation@prod.google.com>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/103505
Reviewed-by: He Gao <hegao@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Miri Amarilio <mirilio@google.com>