From patchwork Fri Mar 15 17:06:39 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 13593798 X-Patchwork-Delegate: bpf@iogearbox.net Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CD4314EB51; Fri, 15 Mar 2024 17:06:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=93.17.236.30 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710522415; cv=none; b=sqePon0axOnjQe5m+/Ijcuiw6OhgmvweVxBwUVP5KO9a1Yun31Pa6Dx4r/zBZfRgogzafIoIF4Y0SxXGdb4l9lTcGIiiAj0/ZW2pUarGtg3/wYVh34mTPUcRg/Pst+B74gf0fFm+4y5ccKUNG2WuV6ofERHT52DO7f2IxC6tOYM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710522415; c=relaxed/simple; bh=sl2cr8YeYnuznXFIaEYjAzPf9uV8OZ4t6aOmppKeo4M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=e4rU2tBetFKm3I7ka4HD4/tzTHlnptxtkntjFs8RmglMbc9oN6TDqecldnJJNk9GBRyvrHIkOXw3d4grMcn6ZdWaKHBy5ecfMBvcEIqVpQgL9Baqp+A/t1pFkpIjY1qm6xZ5+m08W2LHN/k197+xU+eaWuuU6SPau8cIpgbtS3k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=csgroup.eu; spf=pass smtp.mailfrom=csgroup.eu; arc=none smtp.client-ip=93.17.236.30 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=csgroup.eu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=csgroup.eu Received: from localhost (mailhub3.si.c-s.fr [192.168.12.233]) by localhost (Postfix) with ESMTP id 4Tx9dc3pRnz9scZ; Fri, 15 Mar 2024 18:06:44 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id hki_c1Hyr4T0; Fri, 15 Mar 2024 18:06:44 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4Tx9dc2z5Xz9scH; Fri, 15 Mar 2024 18:06:44 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 5CD998B764; Fri, 15 Mar 2024 18:06:44 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id sNFuq5X96zpF; Fri, 15 Mar 2024 18:06:44 +0100 (CET) Received: from PO20335.idsi0.si.c-s.fr (unknown [192.168.233.95]) by messagerie.si.c-s.fr (Postfix) with ESMTP id F31E68B792; Fri, 15 Mar 2024 18:06:42 +0100 (CET) From: Christophe Leroy To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Zi Shen Lim , Catalin Marinas , Will Deacon , "David S. Miller" , David Ahern , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Kui-Feng Lee , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Christophe Leroy , bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Kees Cook Subject: [PATCH bpf-next v3 2/2] bpf: Check return from set_memory_rox() Date: Fri, 15 Mar 2024 18:06:39 +0100 Message-ID: <4d7cc25e937403ac61ae61be06f998f27e631a65.1710522112.git.christophe.leroy@csgroup.eu> X-Mailer: git-send-email 2.43.0 In-Reply-To: <2b9fdb119ef73cfa4516572026ba4936e86aedca.1710522112.git.christophe.leroy@csgroup.eu> References: <2b9fdb119ef73cfa4516572026ba4936e86aedca.1710522112.git.christophe.leroy@csgroup.eu> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1710522399; l=6786; i=christophe.leroy@csgroup.eu; s=20211009; h=from:subject:message-id; bh=sl2cr8YeYnuznXFIaEYjAzPf9uV8OZ4t6aOmppKeo4M=; b=uEhDuYR2vQxMEE08Lyf8q7+SycatJE65mq03LP/hv8VTlqdUA8dd1eVdm6i645YWnbISJ9Pvx JJfbwMO/MDgBvpJU8mDPq5rltRKgNQNq4sp79M/WLthcHDsXl2yHIEa X-Developer-Key: i=christophe.leroy@csgroup.eu; a=ed25519; pk=HIzTzUj91asvincQGOFx6+ZF5AoUuP9GdOtQChs7Mm0= X-Patchwork-Delegate: bpf@iogearbox.net arch_protect_bpf_trampoline() and alloc_new_pack() call set_memory_rox() which can fail, leading to unprotected memory. Take into account return from set_memory_rox() function and add __must_check flag to arch_protect_bpf_trampoline(). Signed-off-by: Christophe Leroy Reviewed-by: Kees Cook --- v3: - Rebased and handled conflict in kernel/bpf/bpf_struct_ops.c v2: - Move list_add_tail(&pack->list, &pack_list) at the end of alloc_new_pack() - Split 2 lines that are reported longer than 80 chars by BPF patchwork's checkpatch report. --- arch/arm64/net/bpf_jit_comp.c | 3 ++- arch/x86/net/bpf_jit_comp.c | 3 ++- include/linux/bpf.h | 2 +- kernel/bpf/bpf_struct_ops.c | 7 +++++-- kernel/bpf/core.c | 29 ++++++++++++++++++++++------- kernel/bpf/trampoline.c | 8 +++++--- net/bpf/bpf_dummy_struct_ops.c | 4 +++- 7 files changed, 40 insertions(+), 16 deletions(-) diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 132c8ffba109..bc16eb694657 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -2176,8 +2176,9 @@ void arch_free_bpf_trampoline(void *image, unsigned int size) bpf_prog_pack_free(image, size); } -void arch_protect_bpf_trampoline(void *image, unsigned int size) +int arch_protect_bpf_trampoline(void *image, unsigned int size) { + return 0; } int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *ro_image, diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 7a56d2d84512..4900b1ee019f 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -3004,8 +3004,9 @@ void arch_free_bpf_trampoline(void *image, unsigned int size) bpf_prog_pack_free(image, size); } -void arch_protect_bpf_trampoline(void *image, unsigned int size) +int arch_protect_bpf_trampoline(void *image, unsigned int size) { + return 0; } int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *image_end, diff --git a/include/linux/bpf.h b/include/linux/bpf.h index d89bdefb42e2..17843e66a1d3 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1116,7 +1116,7 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *i void *func_addr); void *arch_alloc_bpf_trampoline(unsigned int size); void arch_free_bpf_trampoline(void *image, unsigned int size); -void arch_protect_bpf_trampoline(void *image, unsigned int size); +int __must_check arch_protect_bpf_trampoline(void *image, unsigned int size); int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags, struct bpf_tramp_links *tlinks, void *func_addr); diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c index 43356faaa057..ca1d9b87c475 100644 --- a/kernel/bpf/bpf_struct_ops.c +++ b/kernel/bpf/bpf_struct_ops.c @@ -742,8 +742,11 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key, if (err) goto reset_unlock; } - for (i = 0; i < st_map->image_pages_cnt; i++) - arch_protect_bpf_trampoline(st_map->image_pages[i], PAGE_SIZE); + for (i = 0; i < st_map->image_pages_cnt && !err; i++) + err = arch_protect_bpf_trampoline(st_map->image_pages[i], PAGE_SIZE); + + if (err) + goto reset_unlock; if (st_map->map.map_flags & BPF_F_LINK) { err = 0; diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 63f100def31b..1e761c3c66db 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -908,23 +908,31 @@ static LIST_HEAD(pack_list); static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns) { struct bpf_prog_pack *pack; + int err; pack = kzalloc(struct_size(pack, bitmap, BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)), GFP_KERNEL); if (!pack) return NULL; pack->ptr = bpf_jit_alloc_exec(BPF_PROG_PACK_SIZE); - if (!pack->ptr) { - kfree(pack); - return NULL; - } + if (!pack->ptr) + goto out; bpf_fill_ill_insns(pack->ptr, BPF_PROG_PACK_SIZE); bitmap_zero(pack->bitmap, BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE); - list_add_tail(&pack->list, &pack_list); set_vm_flush_reset_perms(pack->ptr); - set_memory_rox((unsigned long)pack->ptr, BPF_PROG_PACK_SIZE / PAGE_SIZE); + err = set_memory_rox((unsigned long)pack->ptr, + BPF_PROG_PACK_SIZE / PAGE_SIZE); + if (err) + goto out_free; + list_add_tail(&pack->list, &pack_list); return pack; + +out_free: + bpf_jit_free_exec(pack->ptr); +out: + kfree(pack); + return NULL; } void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns) @@ -939,9 +947,16 @@ void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns) size = round_up(size, PAGE_SIZE); ptr = bpf_jit_alloc_exec(size); if (ptr) { + int err; + bpf_fill_ill_insns(ptr, size); set_vm_flush_reset_perms(ptr); - set_memory_rox((unsigned long)ptr, size / PAGE_SIZE); + err = set_memory_rox((unsigned long)ptr, + size / PAGE_SIZE); + if (err) { + bpf_jit_free_exec(ptr); + ptr = NULL; + } } goto out; } diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 04fd1abd3661..cc50607f8d8c 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -456,7 +456,9 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut if (err < 0) goto out_free; - arch_protect_bpf_trampoline(im->image, im->size); + err = arch_protect_bpf_trampoline(im->image, im->size); + if (err) + goto out_free; WARN_ON(tr->cur_image && total == 0); if (tr->cur_image) @@ -1072,10 +1074,10 @@ void __weak arch_free_bpf_trampoline(void *image, unsigned int size) bpf_jit_free_exec(image); } -void __weak arch_protect_bpf_trampoline(void *image, unsigned int size) +int __weak arch_protect_bpf_trampoline(void *image, unsigned int size) { WARN_ON_ONCE(size > PAGE_SIZE); - set_memory_rox((long)image, 1); + return set_memory_rox((long)image, 1); } int __weak arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags, diff --git a/net/bpf/bpf_dummy_struct_ops.c b/net/bpf/bpf_dummy_struct_ops.c index de33dc1b0daa..25b75844891a 100644 --- a/net/bpf/bpf_dummy_struct_ops.c +++ b/net/bpf/bpf_dummy_struct_ops.c @@ -133,7 +133,9 @@ int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr, if (err < 0) goto out; - arch_protect_bpf_trampoline(image, PAGE_SIZE); + err = arch_protect_bpf_trampoline(image, PAGE_SIZE); + if (err) + goto out; prog_ret = dummy_ops_call_op(image, args); err = dummy_ops_copy_args(args);