From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-179.mta0.migadu.com (out-179.mta0.migadu.com [91.218.175.179]) (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 B76E012CDBF for ; Tue, 22 Oct 2024 02:20:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729563606; cv=none; b=onaqIyxekM7WiPyUCO6g+Fg6Dz8ycDn0NQ2RthxnP+TpZJlzC/camtHXnu13f3B3RcdsWFSTPwRxnyRrWkdPtiy4xTuflxzIM9asHFQa0ZnG0uawERy129m65Y1Qw+RqkG5pYeyBoMqQ8Td2Wr5Ka8xI+ZctdJprfET4VwDMELQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729563606; c=relaxed/simple; bh=/A/JHvM+Xu6S8RrPguJX8f2DiPe2ij2hlH9qaBDm1qY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Q7oqa0DGwiMXoRsFWemLCrpozaGfA2jmxiUo3Zi0TPhwxDmuLVtx21cqaZ660fagqpG4DtSAVFn+cY6a65QfDIvzmSobTuz6wdll0kXPIf81Whb41r6gdKtjIiVOQAdZz2yZzPNzdCMdgWF5ez3rYxdePoT/t3e0GUS41shZ5+8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=oEYUtqoq; arc=none smtp.client-ip=91.218.175.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="oEYUtqoq" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1729563599; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=I1aEVtnHrE4hISzvygYPrgxHW3Lpc9qC8PgValIZUKU=; b=oEYUtqoqryicx+MPWcoahuAh0u5l7rch8L1MEjq5psKQKFg9qQy+6NxPDeZrWWNGZOqff2 LO5wEJ6E+7Mv/dNOW14I8n/F5I6JmU9CLOdVSNkFrXDRhJvj8saXyM8dN6yrxmDIaMZ6+n jWPtOx4yT/BbQLaDFoLZPljK/JjrmUg= Date: Tue, 22 Oct 2024 10:19:31 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH] slub/slub_kunit:fix a panic due to __kmalloc_cache_noprof incorretly use To: Suren Baghdasaryan , xiaopeitux@foxmail.com Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, yuzhao@google.com, xiaopei01@kylinos.cn, gehao@kylinso.cn, xiongxin@kylinos.cn, Vlastimil Babka References: X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Hao Ge In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 10/22/24 01:42, Suren Baghdasaryan wrote: > On Sun, Oct 20, 2024 at 11:59 PM wrote: >> From: Pei Xiao >> >> 'modprobe slub_kunit',will have a panic.The root cause is that >> __kmalloc_cache_noprof was directly ,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. > I think the root cause of this crash is the bug that is fixed by > https://lore.kernel.org/all/20241020070819.307944-1-hao.ge@linux.dev/. > Do you get this crash if you apply that fix? Yes, this patch has resolved the panic issue. >> 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... >> > CC'ing Vlastimil. > This patch essentially reverts Vlastimil's "mm, slab: don't wrap > internal functions with alloc_hooks()" change. Please check why that > change was needed before proceeding. > If this change is indeed needed, please add: Hi Suren and Vlastimil In fact, besides the panic, there is also a warning here due to directly invoking__kmalloc_cache_noprof Regarding this, do you have any suggestions? [58162.947016] WARNING: CPU: 2 PID: 6210 at ./include/linux/alloc_tag.h:125 alloc_tagging_slab_alloc_hook+0x268/0x27c [58162.957721] Call trace: [58162.957919]  alloc_tagging_slab_alloc_hook+0x268/0x27c [58162.958286]  __kmalloc_cache_noprof+0x14c/0x344 [58162.958615]  test_kmalloc_redzone_access+0x50/0x10c [slub_kunit] [58162.959045]  kunit_try_run_case+0x74/0x184 [kunit] [58162.959401]  kunit_generic_run_threadfn_adapter+0x2c/0x4c [kunit] [58162.959841]  kthread+0x10c/0x118 [58162.960093]  ret_from_fork+0x10/0x20 [58162.960363] ---[ end trace 0000000000000000 ]--- Thanks Best regards Hao > > Fixes: a0a44d9175b349 ("mm, slab: don't wrap internal functions with > alloc_hooks()") > >> Signed-off-by: Pei Xiao >> --- >> include/linux/slab.h | 1 + >> lib/slub_kunit.c | 2 +- >> 2 files changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/include/linux/slab.h b/include/linux/slab.h >> index 10a971c2bde3..0149d36cd311 100644 >> --- a/include/linux/slab.h >> +++ b/include/linux/slab.h >> @@ -827,6 +827,7 @@ void *__kmalloc_cache_noprof(struct kmem_cache *s, gfp_t flags, size_t size) >> void *__kmalloc_cache_node_noprof(struct kmem_cache *s, gfp_t gfpflags, >> int node, size_t size) >> __assume_kmalloc_alignment __alloc_size(4); >> +#define kmalloc_cache(...) alloc_hooks(__kmalloc_cache_noprof(__VA_ARGS__)) >> >> void *__kmalloc_large_noprof(size_t size, gfp_t flags) >> __assume_page_alignment __alloc_size(1); >> diff --git a/lib/slub_kunit.c b/lib/slub_kunit.c >> index 80e39f003344..4bf38f52dbbd 100644 >> --- a/lib/slub_kunit.c >> +++ b/lib/slub_kunit.c >> @@ -141,7 +141,7 @@ static void test_kmalloc_redzone_access(struct kunit *test) >> { >> struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_kmalloc", 32, >> SLAB_KMALLOC|SLAB_STORE_USER|SLAB_RED_ZONE); >> - u8 *p = __kmalloc_cache_noprof(s, GFP_KERNEL, 18); >> + u8 *p = kmalloc_cache(s, GFP_KERNEL, 18); >> >> kasan_disable_current(); >> >> -- >> 2.34.1 >>