Le 01/03/2024 à 08:57, Christophe Leroy a écrit :
> set_memory_rox() can fail, leaving memory unprotected.
>
> Check return and bail out when bpf_jit_binary_lock_ro() returns
> an error.
>
Definitely not a good day for me. I switched maintainers between patch 1
and patch 2 sorry.
Adding [email protected], [email protected], [email protected],
[email protected], [email protected],
[email protected], [email protected], [email protected],
[email protected], [email protected], [email protected],
[email protected], [email protected], [email protected], [email protected],
[email protected], [email protected], [email protected],
[email protected], [email protected], [email protected]
Tell me if I need to resend the series once more.
Thanks
Christophe
> Link: https://github.com/KSPP/linux/issues/7
> Signed-off-by: Christophe Leroy <[email protected]>
> Cc: [email protected] <[email protected]>
> Reviewed-by: Kees Cook <[email protected]>
> Reviewed-by: Puranjay Mohan <[email protected]>
> Reviewed-by: Ilya Leoshkevich <[email protected]> # s390x
> Acked-by: Tiezhu Yang <[email protected]> # LoongArch
> Reviewed-by: Johan Almbladh <[email protected]> # MIPS Part
> ---
> Sorry for the resend, I forgot to flag patch 2 as bpf-next
>
> Previous patch introduces a dependency on this patch because it modifies bpf_prog_lock_ro(), but they are independant.
> It is possible to apply this patch as standalone by handling trivial conflict with unmodified bpf_prog_lock_ro().
>
> v2:
> - Dropped arm64 change following commit 1dad391daef1 ("bpf, arm64: use bpf_prog_pack for memory management")
> - Fixed too long lines reported by checkpatch
> ---
> arch/arm/net/bpf_jit_32.c | 25 ++++++++++++-------------
> arch/loongarch/net/bpf_jit.c | 22 ++++++++++++++++------
> arch/mips/net/bpf_jit_comp.c | 3 ++-
> arch/parisc/net/bpf_jit_core.c | 8 +++++++-
> arch/s390/net/bpf_jit_comp.c | 6 +++++-
> arch/sparc/net/bpf_jit_comp_64.c | 6 +++++-
> arch/x86/net/bpf_jit_comp32.c | 3 +--
> include/linux/filter.h | 5 +++--
> 8 files changed, 51 insertions(+), 27 deletions(-)
>
> diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
> index 1d672457d02f..01516f83a95a 100644
> --- a/arch/arm/net/bpf_jit_32.c
> +++ b/arch/arm/net/bpf_jit_32.c
> @@ -2222,28 +2222,21 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
> /* If building the body of the JITed code fails somehow,
> * we fall back to the interpretation.
> */
> - if (build_body(&ctx) < 0) {
> - image_ptr = NULL;
> - bpf_jit_binary_free(header);
> - prog = orig_prog;
> - goto out_imms;
> - }
> + if (build_body(&ctx) < 0)
> + goto out_free;
> build_epilogue(&ctx);
>
> /* 3.) Extra pass to validate JITed Code */
> - if (validate_code(&ctx)) {
> - image_ptr = NULL;
> - bpf_jit_binary_free(header);
> - prog = orig_prog;
> - goto out_imms;
> - }
> + if (validate_code(&ctx))
> + goto out_free;
> flush_icache_range((u32)header, (u32)(ctx.target + ctx.idx));
>
> if (bpf_jit_enable > 1)
> /* there are 2 passes here */
> bpf_jit_dump(prog->len, image_size, 2, ctx.target);
>
> - bpf_jit_binary_lock_ro(header);
> + if (bpf_jit_binary_lock_ro(header))
> + goto out_free;
> prog->bpf_func = (void *)ctx.target;
> prog->jited = 1;
> prog->jited_len = image_size;
> @@ -2260,5 +2253,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
> bpf_jit_prog_release_other(prog, prog == orig_prog ?
> tmp : orig_prog);
> return prog;
> +
> +out_free:
> + image_ptr = NULL;
> + bpf_jit_binary_free(header);
> + prog = orig_prog;
> + goto out_imms;
> }
>
> diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c
> index e73323d759d0..7dbefd4ba210 100644
> --- a/arch/loongarch/net/bpf_jit.c
> +++ b/arch/loongarch/net/bpf_jit.c
> @@ -1294,16 +1294,19 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
> flush_icache_range((unsigned long)header, (unsigned long)(ctx.image + ctx.idx));
>
> if (!prog->is_func || extra_pass) {
> + int err;
> +
> if (extra_pass && ctx.idx != jit_data->ctx.idx) {
> pr_err_once("multi-func JIT bug %d != %d\n",
> ctx.idx, jit_data->ctx.idx);
> - bpf_jit_binary_free(header);
> - prog->bpf_func = NULL;
> - prog->jited = 0;
> - prog->jited_len = 0;
> - goto out_offset;
> + goto out_free;
> + }
> + err = bpf_jit_binary_lock_ro(header);
> + if (err) {
> + pr_err_once("bpf_jit_binary_lock_ro() returned %d\n",
> + err);
> + goto out_free;
> }
> - bpf_jit_binary_lock_ro(header);
> } else {
> jit_data->ctx = ctx;
> jit_data->image = image_ptr;
> @@ -1334,6 +1337,13 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
> out_offset = -1;
>
> return prog;
> +
> +out_free:
> + bpf_jit_binary_free(header);
> + prog->bpf_func = NULL;
> + prog->jited = 0;
> + prog->jited_len = 0;
> + goto out_offset;
> }
>
> /* Indicate the JIT backend supports mixing bpf2bpf and tailcalls. */
> diff --git a/arch/mips/net/bpf_jit_comp.c b/arch/mips/net/bpf_jit_comp.c
> index a40d926b6513..e355dfca4400 100644
> --- a/arch/mips/net/bpf_jit_comp.c
> +++ b/arch/mips/net/bpf_jit_comp.c
> @@ -1012,7 +1012,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
> bpf_prog_fill_jited_linfo(prog, &ctx.descriptors[1]);
>
> /* Set as read-only exec and flush instruction cache */
> - bpf_jit_binary_lock_ro(header);
> + if (bpf_jit_binary_lock_ro(header))
> + goto out_err;
> flush_icache_range((unsigned long)header,
> (unsigned long)&ctx.target[ctx.jit_index]);
>
> diff --git a/arch/parisc/net/bpf_jit_core.c b/arch/parisc/net/bpf_jit_core.c
> index d6ee2fd45550..979f45d4d1fb 100644
> --- a/arch/parisc/net/bpf_jit_core.c
> +++ b/arch/parisc/net/bpf_jit_core.c
> @@ -167,7 +167,13 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
> bpf_flush_icache(jit_data->header, ctx->insns + ctx->ninsns);
>
> if (!prog->is_func || extra_pass) {
> - bpf_jit_binary_lock_ro(jit_data->header);
> + if (bpf_jit_binary_lock_ro(jit_data->header)) {
> + bpf_jit_binary_free(jit_data->header);
> + prog->bpf_func = NULL;
> + prog->jited = 0;
> + prog->jited_len = 0;
> + goto out_offset;
> + }
> prologue_len = ctx->epilogue_offset - ctx->body_len;
> for (i = 0; i < prog->len; i++)
> ctx->offset[i] += prologue_len;
> diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
> index b418333bb086..e613eebfd349 100644
> --- a/arch/s390/net/bpf_jit_comp.c
> +++ b/arch/s390/net/bpf_jit_comp.c
> @@ -2111,7 +2111,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
> print_fn_code(jit.prg_buf, jit.size_prg);
> }
> if (!fp->is_func || extra_pass) {
> - bpf_jit_binary_lock_ro(header);
> + if (bpf_jit_binary_lock_ro(header)) {
> + bpf_jit_binary_free(header);
> + fp = orig_fp;
> + goto free_addrs;
> + }
> } else {
> jit_data->header = header;
> jit_data->ctx = jit;
> diff --git a/arch/sparc/net/bpf_jit_comp_64.c b/arch/sparc/net/bpf_jit_comp_64.c
> index fa0759bfe498..73bf0aea8baf 100644
> --- a/arch/sparc/net/bpf_jit_comp_64.c
> +++ b/arch/sparc/net/bpf_jit_comp_64.c
> @@ -1602,7 +1602,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
> bpf_flush_icache(header, (u8 *)header + header->size);
>
> if (!prog->is_func || extra_pass) {
> - bpf_jit_binary_lock_ro(header);
> + if (bpf_jit_binary_lock_ro(header)) {
> + bpf_jit_binary_free(header);
> + prog = orig_prog;
> + goto out_off;
> + }
> } else {
> jit_data->ctx = ctx;
> jit_data->image = image_ptr;
> diff --git a/arch/x86/net/bpf_jit_comp32.c b/arch/x86/net/bpf_jit_comp32.c
> index b18ce19981ec..f2be1dcf3b24 100644
> --- a/arch/x86/net/bpf_jit_comp32.c
> +++ b/arch/x86/net/bpf_jit_comp32.c
> @@ -2600,8 +2600,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
> if (bpf_jit_enable > 1)
> bpf_jit_dump(prog->len, proglen, pass + 1, image);
>
> - if (image) {
> - bpf_jit_binary_lock_ro(header);
> + if (image && !bpf_jit_binary_lock_ro(header)) {
> prog->bpf_func = (void *)image;
> prog->jited = 1;
> prog->jited_len = proglen;
> diff --git a/include/linux/filter.h b/include/linux/filter.h
> index 7dd59bccaeec..fc42dcfdbd62 100644
> --- a/include/linux/filter.h
> +++ b/include/linux/filter.h
> @@ -895,10 +895,11 @@ static inline int __must_check bpf_prog_lock_ro(struct bpf_prog *fp)
> return 0;
> }
>
> -static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
> +static inline int __must_check
> +bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
> {
> set_vm_flush_reset_perms(hdr);
> - set_memory_rox((unsigned long)hdr, hdr->size >> PAGE_SHIFT);
> + return set_memory_rox((unsigned long)hdr, hdr->size >> PAGE_SHIFT);
> }
>
> int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);