From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 C3DE71DFD1; Sun, 1 Sep 2024 16:54:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725209667; cv=none; b=Ux5rFIk+87aiFhNWpOifDjmoyH+rOqhSnqgdZ568r+FkL7U3ntnHaf3tegQD/xqGdLRgnUvUilid4ES8l1atAzyAyqfJBKOr8ggKrj6y26uqmevvjRghbTDNcopggGnjWIqX0YUkrY/Lc8+NAjWMXjS/LOlhFY9pwLvTmNHsSGM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725209667; c=relaxed/simple; bh=D4D89SaCKtIiNdKhkNTfEQ9XPI3UrI+egc+qT368TMk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=j5TN898YXMpq7nLqsdx8MJYW9NswfJibnVv6YBWQM98jkLkVYHv/Q1+DPbGFWjJgRIeLUAzfuz5HwhFhsy/XpvUkPiV1csOIc7MSMLAFRumjW/xjsQ4v1p0xvegYoYziqRe9btgsFzaxbEWNHFdahDUBKthmsCILIUeHAGYBvvc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=kgukZ1V8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="kgukZ1V8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3C1DC4CEC3; Sun, 1 Sep 2024 16:54:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1725209667; bh=D4D89SaCKtIiNdKhkNTfEQ9XPI3UrI+egc+qT368TMk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kgukZ1V8jZFoysJDASoTr/rSQoutxPodWi+NPBsbQf0mLXU9KfeHShFhCE5GDCBJb xZ2ac1hofE89RmrkDoYyb/8lkO68OLu/AqYuoGNOjhGf+Or9Z3N4kMcZMagjGKAXQ6 dC4oAg5zWbUyGA10Wfsa4n6S575r+4EeYGaWxlKs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Laurent Vivier , YunQiang Su , Helge Deller , Thorsten Glaser Subject: [PATCH 5.10 108/151] binfmt_misc: pass binfmt_misc flags to the interpreter Date: Sun, 1 Sep 2024 18:17:48 +0200 Message-ID: <20240901160818.172244371@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240901160814.090297276@linuxfoundation.org> References: <20240901160814.090297276@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Laurent Vivier commit 2347961b11d4079deace3c81dceed460c08a8fc1 upstream. It can be useful to the interpreter to know which flags are in use. For instance, knowing if the preserve-argv[0] is in use would allow to skip the pathname argument. This patch uses an unused auxiliary vector, AT_FLAGS, to add a flag to inform interpreter if the preserve-argv[0] is enabled. Note by Helge Deller: The real-world user of this patch is qemu-user, which needs to know if it has to preserve the argv[0]. See Debian bug #970460. Signed-off-by: Laurent Vivier Reviewed-by: YunQiang Su URL: http://bugs.debian.org/970460 Signed-off-by: Helge Deller Cc: Thorsten Glaser Signed-off-by: Greg Kroah-Hartman --- fs/binfmt_elf.c | 5 ++++- fs/binfmt_elf_fdpic.c | 5 ++++- fs/binfmt_misc.c | 4 +++- include/linux/binfmts.h | 4 ++++ include/uapi/linux/binfmts.h | 4 ++++ 5 files changed, 19 insertions(+), 3 deletions(-) --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -186,6 +186,7 @@ create_elf_tables(struct linux_binprm *b unsigned char k_rand_bytes[16]; int items; elf_addr_t *elf_info; + elf_addr_t flags = 0; int ei_index; const struct cred *cred = current_cred(); struct vm_area_struct *vma; @@ -260,7 +261,9 @@ create_elf_tables(struct linux_binprm *b NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); NEW_AUX_ENT(AT_PHNUM, exec->e_phnum); NEW_AUX_ENT(AT_BASE, interp_load_addr); - NEW_AUX_ENT(AT_FLAGS, 0); + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0) + flags |= AT_FLAGS_PRESERVE_ARGV0; + NEW_AUX_ENT(AT_FLAGS, flags); NEW_AUX_ENT(AT_ENTRY, e_entry); NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid)); NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid)); --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -506,6 +506,7 @@ static int create_elf_fdpic_tables(struc char __user *u_platform, *u_base_platform, *p; int loop; int nr; /* reset for each csp adjustment */ + unsigned long flags = 0; #ifdef CONFIG_MMU /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions @@ -648,7 +649,9 @@ static int create_elf_fdpic_tables(struc NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); - NEW_AUX_ENT(AT_FLAGS, 0); + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0) + flags |= AT_FLAGS_PRESERVE_ARGV0; + NEW_AUX_ENT(AT_FLAGS, flags); NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); --- a/fs/binfmt_misc.c +++ b/fs/binfmt_misc.c @@ -191,7 +191,9 @@ static int load_misc_binary(struct linux if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE) goto ret; - if (!(fmt->flags & MISC_FMT_PRESERVE_ARGV0)) { + if (fmt->flags & MISC_FMT_PRESERVE_ARGV0) { + bprm->interp_flags |= BINPRM_FLAGS_PRESERVE_ARGV0; + } else { retval = remove_arg_zero(bprm); if (retval) goto ret; --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -73,6 +73,10 @@ struct linux_binprm { #define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2 #define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT) +/* preserve argv0 for the interpreter */ +#define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3 +#define BINPRM_FLAGS_PRESERVE_ARGV0 (1 << BINPRM_FLAGS_PRESERVE_ARGV0_BIT) + /* Function parameter for binfmt->coredump */ struct coredump_params { const kernel_siginfo_t *siginfo; --- a/include/uapi/linux/binfmts.h +++ b/include/uapi/linux/binfmts.h @@ -18,4 +18,8 @@ struct pt_regs; /* sizeof(linux_binprm->buf) */ #define BINPRM_BUF_SIZE 256 +/* preserve argv0 for the interpreter */ +#define AT_FLAGS_PRESERVE_ARGV0_BIT 0 +#define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT) + #endif /* _UAPI_LINUX_BINFMTS_H */