From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roel Kluin Subject: Re: [PATCH] alpha: kmalloc failure ignored in process_reloc_for_got() Date: Fri, 18 Sep 2009 23:14:01 +0200 Message-ID: <4AB3F819.5020709@gmail.com> References: <4AA6EB5A.5090309@gmail.com> <20090909151848.45db437f.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :content-type:content-transfer-encoding; bh=KTpuz8qv1g/kD0K3ceMdoRVcm2+Jpk77APDRS8a7pIc=; b=mcXwDIZetzGaokuP+0c3uIUKI/nAutG7uAD8up5jhw1aaNJ3xGfYjm+xpZUUL/Buvq 2YfCDbOtg4I2jeIv4EXLrt176+EkMPDfM2KOAqwRtwMFAocfvpmSQJT4K3KEVOF18ZVl PKRvX0YrwTHUywKGRM+JDeLdIheAAJfEwVmHU= In-Reply-To: <20090909151848.45db437f.akpm@linux-foundation.org> Sender: linux-alpha-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Andrew Morton Cc: rth@twiddle.net, linux-alpha@vger.kernel.org Prevent NULL dereference if kmalloc() fails. Signed-off-by: Roel Kluin --- > we should handle this failure properly - back out, clean > everything up, return -ENOMEM to userspace Is this better? I have to admit I didn't build test it, I may be able to do that later. diff --git a/arch/alpha/kernel/module.c b/arch/alpha/kernel/module.c index ebc3c89..5132d98 100644 --- a/arch/alpha/kernel/module.c +++ b/arch/alpha/kernel/module.c @@ -51,7 +51,7 @@ struct got_entry { int got_offset; }; -static inline void +static inline int process_reloc_for_got(Elf64_Rela *rela, struct got_entry *chains, Elf64_Xword *poffset) { @@ -61,7 +61,7 @@ process_reloc_for_got(Elf64_Rela *rela, struct got_entry *g; if (r_type != R_ALPHA_LITERAL) - return; + return 0; for (g = chains + r_sym; g ; g = g->next) if (g->r_addend == r_addend) { @@ -73,6 +73,8 @@ process_reloc_for_got(Elf64_Rela *rela, } g = kmalloc (sizeof (*g), GFP_KERNEL); + if (g == NULL) + return -ENOMEM; g->next = chains[r_sym].next; g->r_addend = r_addend; g->got_offset = *poffset; @@ -84,6 +86,7 @@ process_reloc_for_got(Elf64_Rela *rela, 42 valid relocation types, and a 32-bit field. Co-opt the bits above 256 to store the got offset for this reloc. */ rela->r_info |= g->got_offset << 8; + return 0; } int @@ -94,6 +97,7 @@ module_frob_arch_sections(Elf64_Ehdr *hdr, Elf64_Shdr *sechdrs, Elf64_Rela *rela; Elf64_Shdr *esechdrs, *symtab, *s, *got; unsigned long nsyms, nrela, i; + int ret = 0; esechdrs = sechdrs + hdr->e_shnum; symtab = got = NULL; @@ -137,9 +141,12 @@ module_frob_arch_sections(Elf64_Ehdr *hdr, Elf64_Shdr *sechdrs, if (s->sh_type == SHT_RELA) { nrela = s->sh_size / sizeof(Elf64_Rela); rela = (void *)hdr + s->sh_offset; - for (i = 0; i < nrela; ++i) - process_reloc_for_got(rela+i, chains, + for (i = 0; i < nrela; ++i) { + ret = process_reloc_for_got(rela+i, chains, &got->sh_size); + if (ret != 0) + goto out; + } } /* Free the memory we allocated. */ @@ -150,9 +157,10 @@ module_frob_arch_sections(Elf64_Ehdr *hdr, Elf64_Shdr *sechdrs, kfree(g); } } +out: kfree(chains); - return 0; + return ret; } int