coredump: prevent double-free on an error path in core dumper (f34f9d18) · Commits · 戴 / test

In !CORE_DUMP_USE_REGSET case, if elf_note_info_init fails to allocate memory for info->fields, it frees already allocated stuff and returns error to its caller, fill_note_info. Which in turn returns error to its caller, elf_core_dump. Which jumps to cleanup label and calls free_note_info, which will happily try to free all info->fields again. BOOM. This is the fix. Signed-off-by:

Oleg Nesterov <oleg@redhat.com> Signed-off-by:

Denys Vlasenko <vda.linux@googlemail.com> Cc: Venu Byravarasu <vbyravarasu@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org>

fs/binfmt_elf.c

+4 −15

Original line number	Diff line number	Diff line
		@@ -1696,30 +1696,19 @@ static int elf_note_info_init(struct elf_note_info *info)
		return 0;
		info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
		if (!info->psinfo)
		goto notes_free;
		return 0;
		info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
		if (!info->prstatus)
		goto psinfo_free;
		return 0;
		info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
		if (!info->fpu)
		goto prstatus_free;
		return 0;
		#ifdef ELF_CORE_COPY_XFPREGS
		info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
		if (!info->xfpu)
		goto fpu_free;
		return 0;
		#endif
		return 1;
		#ifdef ELF_CORE_COPY_XFPREGS
		fpu_free:
		kfree(info->fpu);
		#endif
		prstatus_free:
		kfree(info->prstatus);
		psinfo_free:
		kfree(info->psinfo);
		notes_free:
		kfree(info->notes);
		return 0;
		}

		static int fill_note_info(struct elfhdr *elf, int phdrs,

Admin message