From patchwork Sun Oct 20 07:04:27 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hao Ge X-Patchwork-Id: 13843000 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 333F3D3C92F for ; Sun, 20 Oct 2024 07:05:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 14E456B007B; Sun, 20 Oct 2024 03:05:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0FE296B0082; Sun, 20 Oct 2024 03:05:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F07516B0083; Sun, 20 Oct 2024 03:05:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id CB6256B007B for ; Sun, 20 Oct 2024 03:05:07 -0400 (EDT) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 376D2C107C for ; Sun, 20 Oct 2024 07:04:52 +0000 (UTC) X-FDA: 82693093602.18.2D41C78 Received: from out-181.mta1.migadu.com (out-181.mta1.migadu.com [95.215.58.181]) by imf17.hostedemail.com (Postfix) with ESMTP id 559B14000E for ; Sun, 20 Oct 2024 07:04:53 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=MLJN0ipg; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf17.hostedemail.com: domain of hao.ge@linux.dev designates 95.215.58.181 as permitted sender) smtp.mailfrom=hao.ge@linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1729407796; a=rsa-sha256; cv=none; b=nQFknSpFuem88WS1FOhdnsTzFcvr7G3FNXC56vetGthdw9ZqMIwotqmqSEmdhAVB3oH3eA ihzFEUzbnWBU4C7VF2PqHqWT/IjE9mx3FxiHyh5CuxC86Z6UUWu0+zq7qZcx1hAbtUKUhx w+GmBlPmFMwsRh/wuof3HB4dhf6RC+w= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=MLJN0ipg; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf17.hostedemail.com: domain of hao.ge@linux.dev designates 95.215.58.181 as permitted sender) smtp.mailfrom=hao.ge@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1729407796; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=LqIdPb7NeBf33hzfhwQNcfLF0EmzG7i1fDU5vSLYBC4=; b=QQVTJHAZ8Gt8uln4oDXsxfIlGoPMKyC+Z2HkH6vRQ2U1YQuj1oNEfk4yTAPY/SS+mODUZo NRblmc8Jy+4iUg7qaLuq+qZdMBbzLcUvArSRumraTTwaJ+i8hJFySQnnuHmtjT5wp5lbjv JVvKehkJM91Ln3banVDNw2QS/i4m894= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1729407901; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=LqIdPb7NeBf33hzfhwQNcfLF0EmzG7i1fDU5vSLYBC4=; b=MLJN0ipgsiKkCeXjYpmPrtUmW5IkWZc/qemb1EXpJbJSKgBxQARNDBhsJWdVUCskVl3p21 jjW6fv1v3RQL95DemTkKUuonskzGpShulNvvtEAkxIgBSFnSlUNCi8RF5fVIC8cCt5RgDL qGtsxQqsaG8ibrcKCZOMA7YxcCvve8U= From: Hao Ge To: surenb@google.com, kent.overstreet@linux.dev, akpm@linux-foundation.org Cc: yuzhao@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, hao.ge@linux.dev, Hao Ge Subject: [PATCH] mm/codetag: fix null pointer check logic for ref and tag Date: Sun, 20 Oct 2024 15:04:27 +0800 Message-Id: <20241020070427.307702-1-hao.ge@linux.dev> In-Reply-To: <20241018152925.138341-1-hao.ge@linux.dev> References: <20241018152925.138341-1-hao.ge@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: 559B14000E X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: weymznafr56kajj67bsxrbcb68z3d45k X-HE-Tag: 1729407893-250413 X-HE-Meta: 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 iJAAXvoy pu6Y35icKKSiAh//1OuljQSHTEa86cr0ewjnhx6CMJevvnSbYnPlKuFGQv38n9AfrwA+9MtTG6tY4Fq3neYB5nX0Smvc6b8vA82M1l1uZjxqD41KeUkOlJfDnbOib42hYmGnXNPhW4AS2mFgqbUTx0McaezZETJ3cE9Ob X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Hao Ge When we compile and load lib/slub_kunit.c,it will cause a panic. The root cause is that __kmalloc_cache_noprof was directly called instead of kmem_cache_alloc,which resulted in no alloc_tag being allocated.This caused current->alloc_tag to be null,leading to a null pointer dereference in alloc_tag_ref_set. Despite the fact that my colleague Pei Xiao will later fix the code in slub_kunit.c,we still need fix null pointer check logic for ref and tag to avoid panic caused by a null pointer dereference. Here is the log for the panic: [ 74.779373][ T2158] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 [ 74.780130][ T2158] Mem abort info: [ 74.780406][ T2158] ESR = 0x0000000096000004 [ 74.780756][ T2158] EC = 0x25: DABT (current EL), IL = 32 bits [ 74.781225][ T2158] SET = 0, FnV = 0 [ 74.781529][ T2158] EA = 0, S1PTW = 0 [ 74.781836][ T2158] FSC = 0x04: level 0 translation fault [ 74.782288][ T2158] Data abort info: [ 74.782577][ T2158] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [ 74.783068][ T2158] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 74.783533][ T2158] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 74.784010][ T2158] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000105f34000 [ 74.784586][ T2158] [0000000000000020] pgd=0000000000000000, p4d=0000000000000000 [ 74.785293][ T2158] Internal error: Oops: 0000000096000004 [#1] SMP [ 74.785805][ T2158] Modules linked in: slub_kunit kunit ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute ip6table_nat ip6table_mangle 4 [ 74.790661][ T2158] CPU: 0 UID: 0 PID: 2158 Comm: kunit_try_catch Kdump: loaded Tainted: G W N 6.12.0-rc3+ #2 [ 74.791535][ T2158] Tainted: [W]=WARN, [N]=TEST [ 74.791889][ T2158] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 [ 74.792479][ T2158] pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 74.793101][ T2158] pc : alloc_tagging_slab_alloc_hook+0x120/0x270 [ 74.793607][ T2158] lr : alloc_tagging_slab_alloc_hook+0x120/0x270 [ 74.794095][ T2158] sp : ffff800084d33cd0 [ 74.794418][ T2158] x29: ffff800084d33cd0 x28: 0000000000000000 x27: 0000000000000000 [ 74.795095][ T2158] x26: 0000000000000000 x25: 0000000000000012 x24: ffff80007b30e314 [ 74.795822][ T2158] x23: ffff000390ff6f10 x22: 0000000000000000 x21: 0000000000000088 [ 74.796555][ T2158] x20: ffff000390285840 x19: fffffd7fc3ef7830 x18: ffffffffffffffff [ 74.797283][ T2158] x17: ffff8000800e63b4 x16: ffff80007b33afc4 x15: ffff800081654c00 [ 74.798011][ T2158] x14: 0000000000000000 x13: 205d383531325420 x12: 5b5d383734363537 [ 74.798744][ T2158] x11: ffff800084d337e0 x10: 000000000000005d x9 : 00000000ffffffd0 [ 74.799476][ T2158] x8 : 7f7f7f7f7f7f7f7f x7 : ffff80008219d188 x6 : c0000000ffff7fff [ 74.800206][ T2158] x5 : ffff0003fdbc9208 x4 : ffff800081edd188 x3 : 0000000000000001 [ 74.800932][ T2158] x2 : 0beaa6dee1ac5a00 x1 : 0beaa6dee1ac5a00 x0 : ffff80037c2cb000 [ 74.801656][ T2158] Call trace: [ 74.801954][ T2158] alloc_tagging_slab_alloc_hook+0x120/0x270 [ 74.802494][ T2158] __kmalloc_cache_noprof+0x148/0x33c [ 74.802976][ T2158] test_kmalloc_redzone_access+0x4c/0x104 [slub_kunit] [ 74.803607][ T2158] kunit_try_run_case+0x70/0x17c [kunit] [ 74.804124][ T2158] kunit_generic_run_threadfn_adapter+0x2c/0x4c [kunit] [ 74.804768][ T2158] kthread+0x10c/0x118 [ 74.805141][ T2158] ret_from_fork+0x10/0x20 [ 74.805540][ T2158] Code: b9400a80 11000400 b9000a80 97ffd858 (f94012d3) [ 74.806176][ T2158] SMP: stopping secondary CPUs [ 74.808130][ T2158] Starting crashdump kernel... Fixes: e0a955bf7f61 ("mm/codetag: add pgalloc_tag_copy()") Suggested-by: Suren Baghdasaryan Acked-by: Yu Zhao Signed-off-by: Hao Ge --- v3: Modify the code logic based on Suren's suggestions. Update title and commit message due to code logic change. Add Suggested-by: Suren Baghdasaryan Add Acked-by: Yu Zhao v2: Modify the errors in the title and commit message. Remove the empty lines that were mistakenly added in version v1. --- include/linux/alloc_tag.h | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/include/linux/alloc_tag.h b/include/linux/alloc_tag.h index 1f0a9ff23a2c..941deffc590d 100644 --- a/include/linux/alloc_tag.h +++ b/include/linux/alloc_tag.h @@ -135,18 +135,21 @@ static inline void alloc_tag_sub_check(union codetag_ref *ref) {} #endif /* Caller should verify both ref and tag to be valid */ -static inline void __alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *tag) +static inline bool __alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *tag) { alloc_tag_add_check(ref, tag); if (!ref || !tag) - return; + return false; ref->ct = &tag->ct; + return true; } -static inline void alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *tag) +static inline bool alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *tag) { - __alloc_tag_ref_set(ref, tag); + if (unlikely(!__alloc_tag_ref_set(ref, tag))) + return false; + /* * We need in increment the call counter every time we have a new * allocation or when we split a large allocation into smaller ones. @@ -154,12 +157,13 @@ static inline void alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *t * counter because when we free each part the counter will be decremented. */ this_cpu_inc(tag->counters->calls); + return true; } static inline void alloc_tag_add(union codetag_ref *ref, struct alloc_tag *tag, size_t bytes) { - alloc_tag_ref_set(ref, tag); - this_cpu_add(tag->counters->bytes, bytes); + if (likely(alloc_tag_ref_set(ref, tag))) + this_cpu_add(tag->counters->bytes, bytes); } static inline void alloc_tag_sub(union codetag_ref *ref, size_t bytes)