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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id k3-20020a170902ce0300b00176b63535adsm144895plg.260.2022.10.28.19.54.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Oct 2022 19:54:34 -0700 (PDT) From: Kees Cook To: Alexei Starovoitov Cc: Kees Cook , Daniel Borkmann , John Fastabend , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH bpf-next v2 1/3] bpf/verifier: Fix potential memory leak in array reallocation Date: Fri, 28 Oct 2022 19:54:30 -0700 Message-Id: <20221029025433.2533810-1-keescook@chromium.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221029024444.gonna.633-kees@kernel.org> References: <20221029024444.gonna.633-kees@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1619; h=from:subject; bh=R3dgFp0WNEaE5DyG4WxLN0RrYSteV9dcGhEkWDiXzvE=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBjXJXnp3Ea19E3WkEr9o8FAh2necyessJ+7If2U/2x vL4vvxyJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCY1yV5wAKCRCJcvTf3G3AJkffD/ 495y2Ah8ie6a9DRLJ56z541wAuD1q1LglGfd3C1cbGoOR76OU5kPPGuDGY8Npallv6VrFij94Z81sA 4zyFjmaROOGYwctXbNfnfbp5rKO7FMsPe+NZ72GoCxuE6dWHc9XOsS2KRMAc4SaeDz8ZgZSVr3hZTX CeMuHtwh0BnXQ8JR4WstYUjUpLWQy4S9kpJJJ2KicSVC8iEWYWkavGVV3zZT4gDE1j4bKhq0FH1iwa iBZ+KB4Ubg7hEgqx/2o6raZKsUlCQLv5C0krkqAeKTisXS/5x4cqu1LYGxE4KKXvKjMyfv+/lXp6XR GXYnwp7rReKyUA+ajg3BVlvXPvGkLW3R1Zd3vUbg4HpFEGF+MkTCsRz5Tvbb4B/M7J9PnIWBEL4g4I dccXIQa3RVocJ/4jixQTLo8BBqkTub/60/5zl5mJVCUdD0Vz7XTh52FqroKRh1Vy1TSDYseP+AZfh+ p0WkmHXJKX9n31sJSgSB7J+rz1bu1syxfbeQf8jMKFgQ+EeH1SxGlNnTbS2DBF2Akh0vNbJMsVNuRr tDAVlwSuRS9YURTtlMBMpJ27+Sqb6mGhKWpkHoqo3hfTM5rjKK8caNpk+TFmRkiXcyFHaNHIAYf33j xCahoS/rV03jEY2g6AYq81K4kUoYC+3ycJMhysPhSQn5B04YHUtjliF3oaEg== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" If an error (NULL) is returned by krealloc(), callers of realloc_array() were setting their allocation pointers to NULL, but on error krealloc() does not touch the original allocation. This would result in a memory resource leak. Instead, free the old allocation on the error handling path. Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: John Fastabend Cc: Andrii Nakryiko Cc: Martin KaFai Lau Cc: Song Liu Cc: Yonghong Song Cc: KP Singh Cc: Stanislav Fomichev Cc: Hao Luo Cc: Jiri Olsa Cc: bpf@vger.kernel.org Signed-off-by: Kees Cook Reviewed-by: Bill Wendling --- kernel/bpf/verifier.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 014ee0953dbd..eb8c34db74c7 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1027,12 +1027,17 @@ static void *copy_array(void *dst, const void *src,= size_t n, size_t size, gfp_t */ static void *realloc_array(void *arr, size_t old_n, size_t new_n, size_t s= ize) { + void *new_arr; + if (!new_n || old_n =3D=3D new_n) goto out; =20 - arr =3D krealloc_array(arr, new_n, size, GFP_KERNEL); - if (!arr) + new_arr =3D krealloc_array(arr, new_n, size, GFP_KERNEL); + if (!new_arr) { + kfree(arr); return NULL; + } + arr =3D new_arr; =20 if (new_n > old_n) memset(arr + old_n * size, 0, (new_n - old_n) * size); --=20 2.34.1 From nobody Wed Apr 8 19:54:58 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 590E3C38A02 for ; Sat, 29 Oct 2022 02:55:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229500AbiJ2CzX (ORCPT ); Fri, 28 Oct 2022 22:55:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40718 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229817AbiJ2CzQ (ORCPT ); Fri, 28 Oct 2022 22:55:16 -0400 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 590812494B for ; Fri, 28 Oct 2022 19:54:38 -0700 (PDT) Received: by mail-pj1-x102c.google.com with SMTP id v4-20020a17090a088400b00212cb0ed97eso6045328pjc.5 for ; Fri, 28 Oct 2022 19:54:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=8tl37lwqGAPyFTOLYOb65cx9juvzNTvoWHjwD7xYuFQ=; b=Cd9tmgsJJdWf0loxgAfE2HPeppCYbVz4D5gJ5tQcKB6L+ovA12Ew9mChsqPQXbuSUK P+EKoy+7WwL8q2rj931dqINtyZh6kEENAED1WS3uD8thf4KfTiTnMhSt3//hP3fVmfyz 3nim0DVM7yPvIiHCyNEkq1nGp3MR8CSWdqGbo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=8tl37lwqGAPyFTOLYOb65cx9juvzNTvoWHjwD7xYuFQ=; b=xDv2/7YxGUmV5JbvKfc42+m/6ZGdWzkv4wKDfoZXialVI0rJNW3mPVuUOOvIqD8XU3 Dfk8fyjbCiEV7wxwAqJBMHw5mVcf4OiR6nnpx8FuEKnNBHkPY/454TgPg+vJTi7GdlI3 qgPu9U8WfMnI0qUg/W1MdX6ytUoq7eg5985bv3qdlELKb0R6H5qAkb3fPZQUgCLoJNHw chqba8QKGKz0J2s73yRvCOSrz81c6KKHvmdMUSVPqgz448rh6ZlLad6mGFuIiEtHBsVT 28fAWetd7oFpHXHwKuCiSvLvNBYsp32aw9gqxUk1Mn4u0Nk2vIg4xG1kJrEZkLY3IMOM jA4g== X-Gm-Message-State: ACrzQf1oLgd6ay4twia00/07Az7wXX/xgC8eanPfR33o1Ml8gQiHfS0f uobg4SGZU3UgzZJjYJZ5OArpRg== X-Google-Smtp-Source: AMsMyM4pP7ShODaS+Vv2buYU2g/jVJzW9tIyo/uOr9kvGNsRBVt6bMvVzIkugYCjOKGHoyJnVIuKXA== X-Received: by 2002:a17:902:6b45:b0:186:878e:3b92 with SMTP id g5-20020a1709026b4500b00186878e3b92mr2222756plt.173.1667012077781; Fri, 28 Oct 2022 19:54:37 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id p68-20020a625b47000000b0056b9c2699cesm170223pfb.46.2022.10.28.19.54.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Oct 2022 19:54:34 -0700 (PDT) From: Kees Cook To: Alexei Starovoitov Cc: Kees Cook , Daniel Borkmann , John Fastabend , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH bpf-next v2 2/3] bpf/verifier: Use kmalloc_size_roundup() to match ksize() usage Date: Fri, 28 Oct 2022 19:54:31 -0700 Message-Id: <20221029025433.2533810-2-keescook@chromium.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221029024444.gonna.633-kees@kernel.org> References: <20221029024444.gonna.633-kees@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2473; h=from:subject; bh=cAZzQf4nJI/2AavYPElJQqPl11xZNu41P29+G33SJ9M=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBjXJXnQGC8fPZwalh9l14/jG4kobQw8yjDcH8NbjSJ /XPIE3yJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCY1yV5wAKCRCJcvTf3G3AJtu9EA CXJjb2SNBE0dlmaXWQ51VUbBpWbuJYO6erazxkwDl20aLVHHY3Axth5HAjZff0RAgI1VuEgK0XZp1r RE0TT1eYl9G5ixdAC59qd1CyEHIcrq8+ifEZo8FgjuCM+csjbDGyrKYcgszia+gdt0jTBIbTc9RPDk h49CV0gy5UmirPGgX8dGIyGnpKI4FNyJSxPrtKEYB1NNT0NKDCYYx+RfELfzFCEUHszzQjq2QGPcoS MQCDLvOy6b2RiQLtsraXNMaGqb45mx9P5O9CTysRsnzDMvCA7NXwCuQuXsdjO/2HsBfxhz7Ar/YR9W Q9PmyZ/L0otSPcROBpRG2q6CUmDpOthzfBzcW58TTyDeLip32DmQpFbyiXtSgKMujj/DUh8fnY/DR8 2j1VH+mqdaYP7FiWIMA+ed88554A/22x76JzNS5Caj75Gk5klIWA9DRXxqyAIhkWj0AZZY0oDA+/bI BaXI9irmdN/ojaCMS7GiewpfSz1XqXzoo+a2/IHb6qtOmcwGzuRXjvvCvZc3nO7FmlQUzB23V63ndC YIDPWXj/8EpTHHzYIkslH/ROZny/WlLvaMSrDlNnM8CWhQz5RGWiBaLDqtr2+lr8CzFydwOd9JaxoT 275n7Yb5433TpvdeSuKo/IQkPJI9tpzIZx8/08+btiQkdvPTHYsFe9hnV9Iw== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Round up allocations with kmalloc_size_roundup() so that the verifier's use of ksize() is always accurate and no special handling of the memory is needed by KASAN, UBSAN_BOUNDS, nor FORTIFY_SOURCE. Pass the new size information back up to callers so they can use the space immediately, so array resizing to happen less frequently as well. Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: John Fastabend Cc: Andrii Nakryiko Cc: Martin KaFai Lau Cc: Song Liu Cc: Yonghong Song Cc: KP Singh Cc: Stanislav Fomichev Cc: Hao Luo Cc: Jiri Olsa Cc: bpf@vger.kernel.org Signed-off-by: Kees Cook --- kernel/bpf/verifier.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index eb8c34db74c7..1c040d27b8f6 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1008,9 +1008,9 @@ static void *copy_array(void *dst, const void *src, s= ize_t n, size_t size, gfp_t if (unlikely(check_mul_overflow(n, size, &bytes))) return NULL; =20 - if (ksize(dst) < bytes) { + if (ksize(dst) < ksize(src)) { kfree(dst); - dst =3D kmalloc_track_caller(bytes, flags); + dst =3D kmalloc_track_caller(kmalloc_size_roundup(bytes), flags); if (!dst) return NULL; } @@ -1027,12 +1027,14 @@ static void *copy_array(void *dst, const void *src,= size_t n, size_t size, gfp_t */ static void *realloc_array(void *arr, size_t old_n, size_t new_n, size_t s= ize) { + size_t alloc_size; void *new_arr; =20 if (!new_n || old_n =3D=3D new_n) goto out; =20 - new_arr =3D krealloc_array(arr, new_n, size, GFP_KERNEL); + alloc_size =3D kmalloc_size_roundup(size_mul(new_n, size)); + new_arr =3D krealloc(arr, alloc_size, GFP_KERNEL); if (!new_arr) { kfree(arr); return NULL; @@ -2504,9 +2506,11 @@ static int push_jmp_history(struct bpf_verifier_env = *env, { u32 cnt =3D cur->jmp_history_cnt; struct bpf_idx_pair *p; + size_t alloc_size; =20 cnt++; - p =3D krealloc(cur->jmp_history, cnt * sizeof(*p), GFP_USER); + alloc_size =3D kmalloc_size_roundup(size_mul(cnt, sizeof(*p))); + p =3D krealloc(cur->jmp_history, alloc_size, GFP_USER); if (!p) return -ENOMEM; p[cnt - 1].idx =3D env->insn_idx; --=20 2.34.1 From nobody Wed Apr 8 19:54:58 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DDB5BFA3741 for ; Sat, 29 Oct 2022 02:55:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229823AbiJ2CzR (ORCPT ); Fri, 28 Oct 2022 22:55:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40486 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229779AbiJ2CzK (ORCPT ); Fri, 28 Oct 2022 22:55:10 -0400 Received: from mail-pl1-x633.google.com (mail-pl1-x633.google.com [IPv6:2607:f8b0:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E675C24099 for ; Fri, 28 Oct 2022 19:54:37 -0700 (PDT) Received: by mail-pl1-x633.google.com with SMTP id y4so6392350plb.2 for ; Fri, 28 Oct 2022 19:54:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=3aOLv5bd0FLV/mnE8/fEeex6Wf+bGxAwiWHAjCPeob8=; b=F1CIddvjILhqwJkQTMNC9hHvJYNArr9ey/ZbzNYqitzzHQZy3r7uM2qGWEgnpwLm8D 2kScoECk2psL1KqyxHSF4Rd2eD8r7UkizqsMCsaURAOY8eTeMT9EhLycnkY/5dYIVixg Phcsf1C/VDjddGLVWbrt40HOPyI0z5cfUGem0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=3aOLv5bd0FLV/mnE8/fEeex6Wf+bGxAwiWHAjCPeob8=; b=JBcJZYWqkXe4JOS+839pEsytLY0HKWCEzYQ8CHN6gGagcFLtfC323XW6pwQ/Isix7m mfN3ryk0pkQ9egoGFhJiHbz7C9Iuo+nCIKEvx0Asm50vjspxDN3W9vBI4z3WuZiofB5l k87ZKm7VtS+hH53gEQJx/Wh8yG2AU3r21S13SqkjMjbglqY1V7wRqTCzVYFNgZOQz9Dl UgPWW9ALVSzpr8YY6r9zkICAeUgNXh45UH19PbSi35vx3ASBox0NyKjxrGEMqkTZXrmy xGBCC4aYPs0Nrq+Fp6jGfV5HeCG+i7MaJJxNE8sKtnwrKwmnDDb4TvajIZ08yTKJyCzU jVAg== X-Gm-Message-State: ACrzQf3ZQqcKWH4FK7eQMq1OpU1I4cDSDU70FGCqUs5/BsTl95Qs6pZQ ggXAJgIAlFK1SiexEd30tfvFnQ== X-Google-Smtp-Source: AMsMyM6HJPQNNHUKo0hqSZ77eYX6lSBHvTuXFvuJmE1nVwBFZI8X4MsvRQFTWCL3yLz9vbqzCuWTBw== X-Received: by 2002:a17:902:dad1:b0:183:243c:d0d0 with SMTP id q17-20020a170902dad100b00183243cd0d0mr2229535plx.157.1667012077434; Fri, 28 Oct 2022 19:54:37 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id p15-20020a634f4f000000b00429c5270710sm166610pgl.1.2022.10.28.19.54.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Oct 2022 19:54:34 -0700 (PDT) From: Kees Cook To: Alexei Starovoitov Cc: Kees Cook , Daniel Borkmann , John Fastabend , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH bpf-next v2 3/3] bpf/verifier: Take advantage of full allocation sizes Date: Fri, 28 Oct 2022 19:54:32 -0700 Message-Id: <20221029025433.2533810-3-keescook@chromium.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221029024444.gonna.633-kees@kernel.org> References: <20221029024444.gonna.633-kees@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3544; h=from:subject; bh=kUtgUSzjHG/StpxeZ/gAkJuSWQ81P7If0wKJuguKsQA=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBjXJXoKq5ZWOaEe0w9wu2rU5+gTlHcFnfDONzx5rl8 2MO2kVmJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCY1yV6AAKCRCJcvTf3G3AJjZFEA CbaiZHl1X/Eo7Q6u7OrXXEEu/Fc8P8Egz+2f9weQmvTFT6k8pHEJ646zRGYaElHNuF8dWLLFMJzM1Y uArHQVBqs6LQJ42PuY5l3YGl7j7pmWZwLgscvoR5jyYaXK+/r4zeRdhSbld8X/9cqZ6Jxk8SiPWveK dR/nJPs+tNkPLMdmyWbiEcz5A5+/tAzCBLmZjrgFBEokROEOl+TXx4IIpQbyqgzIDH3+gZ70I1NUhW lPjsvBvh52LVVOaWPV+GLV49VL/tK9veQLcWdWjSMzbnibeWn/xi9OCf94VNP/sAud9eO3w2PFBOij dA4dB88NxOwPgBSoN72V20mybNtqDdfmFCsI3osTyRAdnS+aFgUZ46I72yHpxd016UXEu6QcEUoTgu hKZz6nCyDNN/LfR5C6KER5YAYDzU+MC2uVFAdvE8GeabTsB5cO9kmujEadXdzd4j3C/ZCm6NsUSXG8 LtqGbSpbXDkuteqDDR8dhqIwYkp1t6sajZpOkWVSrKCyEaP65KGhzNwurPBOwlkjyg/K1aQxVys/l4 WVq86oBHhGxemD+KPFGaiLNBxljDw59+kpBi/I8VyCjT7lfHHIqmjFTKNREDkjg5izXZHA9wWJEJ7z CXrUKoUSAdUN08z2u+RbVOxApyfeLHAPi9Jty6yKPofgiYJneRRiZCO0gQjg== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Since the full kmalloc bucket size is being explicitly allocated, pass back the resulting details to take advantage of the full size so that reallocation checking will be needed less frequently. Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: John Fastabend Cc: Andrii Nakryiko Cc: Martin KaFai Lau Cc: Song Liu Cc: Yonghong Song Cc: KP Singh Cc: Stanislav Fomichev Cc: Hao Luo Cc: Jiri Olsa Cc: bpf@vger.kernel.org Signed-off-by: Kees Cook --- kernel/bpf/verifier.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 1c040d27b8f6..e58b554e862b 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1020,20 +1020,23 @@ static void *copy_array(void *dst, const void *src,= size_t n, size_t size, gfp_t return dst ? dst : ZERO_SIZE_PTR; } =20 -/* resize an array from old_n items to new_n items. the array is reallocat= ed if it's too - * small to hold new_n items. new items are zeroed out if the array grows. +/* Resize an array from old_n items to *new_n items. The array is + * reallocated if it's too small to hold *new_n items. New items are + * zeroed out if the array grows. Allocation is rounded up to next kmalloc + * bucket size to reduce frequency of resizing. *new_n contains the new + * total number of items that will fit. * - * Contrary to krealloc_array, does not free arr if new_n is zero. + * Contrary to krealloc, does not free arr if new_n is zero. */ -static void *realloc_array(void *arr, size_t old_n, size_t new_n, size_t s= ize) +static void *realloc_array(void *arr, size_t old_n, size_t *new_n, size_t = size) { size_t alloc_size; void *new_arr; =20 - if (!new_n || old_n =3D=3D new_n) + if (!new_n || !*new_n || old_n =3D=3D *new_n) goto out; =20 - alloc_size =3D kmalloc_size_roundup(size_mul(new_n, size)); + alloc_size =3D kmalloc_size_roundup(size_mul(*new_n, size)); new_arr =3D krealloc(arr, alloc_size, GFP_KERNEL); if (!new_arr) { kfree(arr); @@ -1041,8 +1044,9 @@ static void *realloc_array(void *arr, size_t old_n, s= ize_t new_n, size_t size) } arr =3D new_arr; =20 - if (new_n > old_n) - memset(arr + old_n * size, 0, (new_n - old_n) * size); + *new_n =3D alloc_size / size; + if (*new_n > old_n) + memset(arr + old_n * size, 0, (*new_n - old_n) * size); =20 out: return arr ? arr : ZERO_SIZE_PTR; @@ -1074,7 +1078,7 @@ static int copy_stack_state(struct bpf_func_state *ds= t, const struct bpf_func_st =20 static int resize_reference_state(struct bpf_func_state *state, size_t n) { - state->refs =3D realloc_array(state->refs, state->acquired_refs, n, + state->refs =3D realloc_array(state->refs, state->acquired_refs, &n, sizeof(struct bpf_reference_state)); if (!state->refs) return -ENOMEM; @@ -1090,11 +1094,12 @@ static int grow_stack_state(struct bpf_func_state *= state, int size) if (old_n >=3D n) return 0; =20 - state->stack =3D realloc_array(state->stack, old_n, n, sizeof(struct bpf_= stack_state)); + state->stack =3D realloc_array(state->stack, old_n, &n, + sizeof(struct bpf_stack_state)); if (!state->stack) return -ENOMEM; =20 - state->allocated_stack =3D size; + state->allocated_stack =3D n * BPF_REG_SIZE; return 0; } =20 --=20 2.34.1