From patchwork Mon Jun 24 16:36:59 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 13709882 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 E726419DFAD; Mon, 24 Jun 2024 16:37:26 +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=1719247047; cv=none; b=hNQY1t5zYUgY+1RR767N4NYBsk9kBE57VApuSRqC7CmR6+s+E1fcNMYksic7ZVRb8ulYcd7q6YBFaaf3zSVRRakM2BKaZo6Y0RMIfu3M/aD2ZA7O87lKs7iz4jbnDxcSlnFpVYwwBhaJHyUh6Rh66GOFTzKXxMsS+6QDXrN0AVg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719247047; c=relaxed/simple; bh=EwPpX0S1DTr+6EvIenNObE+xZCXTGGAFxEeI1J4w98A=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=narmM+bHjVFqvjqiIo4RmzwxCI8QmrDCM+SDQ7LHFSC1BuB5fLY2msZQAPmxuQorc5qXbE5kOMYP80hRjp23yXtZDZ3q6WXbQb59Jn2lBLbMrorDeeKklVRpfF8knrlVv902ExY8UEXAEds/z4CZMocQTxCOPqFURwyTANFiYwc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FhTmssAm; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FhTmssAm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B69CC32782; Mon, 24 Jun 2024 16:37:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719247046; bh=EwPpX0S1DTr+6EvIenNObE+xZCXTGGAFxEeI1J4w98A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FhTmssAmbe2m7XIZuY8gNTeVo+Lkit5BxwKeUJVUTZwbQDs+G38+66PslSvzLgbPX 5VKaiDIhlfUucsc4cjoE7TqvsIBTcMhplYbPShFl5s9bpnQzl7TNnyubJlrQWYBJtL +/n0rSYNeyLLM8kjj7zO4V6y9CBf8tcSacuRTYHi/44G5yRnMmt4Ieqoj6GlBy9sPc dZ2nLCKQKHprpGR0yeVZy2oKdDUOIcxuh6Y4DBO8vU3exBZJH7F0XMADo/asFimmTq sKPNph/E2CBt9PEnVWdZ6rFALDcWj8IxJTdgWx9kRIgFVlh8ERnRYJV9VwZ/nU3ne/ suhAPd1WlO1Pw== From: Arnd Bergmann To: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Arnd Bergmann , Thomas Bogendoerfer , linux-mips@vger.kernel.org, Helge Deller , linux-parisc@vger.kernel.org, "David S. Miller" , Andreas Larsson , sparclinux@vger.kernel.org, Michael Ellerman , Nicholas Piggin , Christophe Leroy , "Naveen N . Rao" , linuxppc-dev@lists.ozlabs.org, Brian Cain , linux-hexagon@vger.kernel.org, Guo Ren , linux-csky@vger.kernel.org, Heiko Carstens , linux-s390@vger.kernel.org, Rich Felker , John Paul Adrian Glaubitz , linux-sh@vger.kernel.org, "H. Peter Anvin" , Alexander Viro , Christian Brauner , linux-fsdevel@vger.kernel.org, libc-alpha@sourceware.org, musl@lists.openwall.com, stable@vger.kernel.org Subject: [PATCH v2 01/13] ftruncate: pass a signed offset Date: Mon, 24 Jun 2024 18:36:59 +0200 Message-Id: <20240624163707.299494-2-arnd@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240624163707.299494-1-arnd@kernel.org> References: <20240624163707.299494-1-arnd@kernel.org> Precedence: bulk X-Mailing-List: linux-sh@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Arnd Bergmann The old ftruncate() syscall, using the 32-bit off_t misses a sign extension when called in compat mode on 64-bit architectures. As a result, passing a negative length accidentally succeeds in truncating to file size between 2GiB and 4GiB. Changing the type of the compat syscall to the signed compat_off_t changes the behavior so it instead returns -EINVAL. The native entry point, the truncate() syscall and the corresponding loff_t based variants are all correct already and do not suffer from this mistake. Fixes: 3f6d078d4acc ("fix compat truncate/ftruncate") Reviewed-by: Christian Brauner Cc: stable@vger.kernel.org Signed-off-by: Arnd Bergmann --- fs/open.c | 4 ++-- include/linux/compat.h | 2 +- include/linux/syscalls.h | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/open.c b/fs/open.c index 89cafb572061..50e45bc7c4d8 100644 --- a/fs/open.c +++ b/fs/open.c @@ -202,13 +202,13 @@ long do_sys_ftruncate(unsigned int fd, loff_t length, int small) return error; } -SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length) +SYSCALL_DEFINE2(ftruncate, unsigned int, fd, off_t, length) { return do_sys_ftruncate(fd, length, 1); } #ifdef CONFIG_COMPAT -COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_ulong_t, length) +COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_off_t, length) { return do_sys_ftruncate(fd, length, 1); } diff --git a/include/linux/compat.h b/include/linux/compat.h index 233f61ec8afc..56cebaff0c91 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -608,7 +608,7 @@ asmlinkage long compat_sys_fstatfs(unsigned int fd, asmlinkage long compat_sys_fstatfs64(unsigned int fd, compat_size_t sz, struct compat_statfs64 __user *buf); asmlinkage long compat_sys_truncate(const char __user *, compat_off_t); -asmlinkage long compat_sys_ftruncate(unsigned int, compat_ulong_t); +asmlinkage long compat_sys_ftruncate(unsigned int, compat_off_t); /* No generic prototype for truncate64, ftruncate64, fallocate */ asmlinkage long compat_sys_openat(int dfd, const char __user *filename, int flags, umode_t mode); diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 9104952d323d..ba9337709878 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -418,7 +418,7 @@ asmlinkage long sys_listmount(const struct mnt_id_req __user *req, u64 __user *mnt_ids, size_t nr_mnt_ids, unsigned int flags); asmlinkage long sys_truncate(const char __user *path, long length); -asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length); +asmlinkage long sys_ftruncate(unsigned int fd, off_t length); #if BITS_PER_LONG == 32 asmlinkage long sys_truncate64(const char __user *path, loff_t length); asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length);