From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754758AbbIPR5V (ORCPT ); Wed, 16 Sep 2015 13:57:21 -0400 Received: from mail.kernel.org ([198.145.29.136]:55775 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753108AbbIPR5S (ORCPT ); Wed, 16 Sep 2015 13:57:18 -0400 Date: Wed, 16 Sep 2015 10:57:15 -0700 From: Jaegeuk Kim To: Chao Yu Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, stable@vger.kernel.org Subject: Re: [f2fs-dev] [PATCH v4] f2fs crypto: allocate buffer for decrypting filename Message-ID: <20150916175715.GA99097@jaegeuk-mac02.mot.com> References: <1441936062-69511-1-git-send-email-jaegeuk@kernel.org> <20150911224550.GA73045@jaegeuk-mac02.mot.com> <20150915165215.GA82346@jaegeuk-mac02.mot.com> <000901d0f068$1a1bd100$4e537300$@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <000901d0f068$1a1bd100$4e537300$@samsung.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks Chao, Change log from v3: o enhance the code with proper error handling Change log from v1: o fix wrong pointer assignment Chang log from v2: o add one more missing call path: f2fs_encrypted_follow_link >>From efdbbbb4c9bb6519e3c10ec5081a2dcdbaca81d2 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Thu, 3 Sep 2015 13:38:23 -0700 Subject: [PATCH] f2fs crypto: allocate buffer for decrypting filename We got dentry pages from high_mem, and its address space directly goes into the decryption path via f2fs_fname_disk_to_usr. But, sg_init_one assumes the address is not from high_mem, so we can get this panic since it doesn't call kmap_high but kunmap_high is triggered at the end. kernel BUG at ../../../../../../kernel/mm/highmem.c:290! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM ... (kunmap_high+0xb0/0xb8) from [] (__kunmap_atomic+0xa0/0xa4) (__kunmap_atomic+0xa0/0xa4) from [] (blkcipher_walk_done+0x128/0x1ec) (blkcipher_walk_done+0x128/0x1ec) from [] (crypto_cbc_decrypt+0xc0/0x170) (crypto_cbc_decrypt+0xc0/0x170) from [] (crypto_cts_decrypt+0xc0/0x114) (crypto_cts_decrypt+0xc0/0x114) from [] (async_decrypt+0x40/0x48) (async_decrypt+0x40/0x48) from [] (f2fs_fname_disk_to_usr+0x124/0x304) (f2fs_fname_disk_to_usr+0x124/0x304) from [] (f2fs_fill_dentries+0xac/0x188) (f2fs_fill_dentries+0xac/0x188) from [] (f2fs_readdir+0x1f0/0x300) (f2fs_readdir+0x1f0/0x300) from [] (vfs_readdir+0x90/0xb4) (vfs_readdir+0x90/0xb4) from [] (SyS_getdents64+0x64/0xcc) (SyS_getdents64+0x64/0xcc) from [] (ret_fast_syscall+0x0/0x30) Cc: Signed-off-by: Jaegeuk Kim --- fs/f2fs/dir.c | 13 ++++++++++--- fs/f2fs/namei.c | 10 +++++++++- 2 files changed, 19 insertions(+), 4 deletions(-) diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index 8f15fc1..6726c4a 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -787,7 +787,6 @@ bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, else d_type = DT_UNKNOWN; - /* encrypted case */ de_name.name = d->filename[bit_pos]; de_name.len = le16_to_cpu(de->name_len); @@ -795,12 +794,20 @@ bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, int save_len = fstr->len; int ret; + de_name.name = kmalloc(de_name.len, GFP_NOFS); + if (!de_name.name) + return false; + + memcpy(de_name.name, d->filename[bit_pos], de_name.len); + ret = f2fs_fname_disk_to_usr(d->inode, &de->hash_code, &de_name, fstr); - de_name = *fstr; - fstr->len = save_len; + kfree(de_name.name); if (ret < 0) return true; + + de_name = *fstr; + fstr->len = save_len; } if (!dir_emit(ctx, de_name.name, de_name.len, diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c index a680bf3..dfa01c8 100644 --- a/fs/f2fs/namei.c +++ b/fs/f2fs/namei.c @@ -947,8 +947,13 @@ static const char *f2fs_encrypted_follow_link(struct dentry *dentry, void **cook /* Symlink is encrypted */ sd = (struct f2fs_encrypted_symlink_data *)caddr; - cstr.name = sd->encrypted_path; cstr.len = le16_to_cpu(sd->len); + cstr.name = kmalloc(cstr.len, GFP_NOFS); + if (!cstr.name) { + res = -ENOMEM; + goto errout; + } + memcpy(cstr.name, sd->encrypted_path, cstr.len); /* this is broken symlink case */ if (cstr.name[0] == 0 && cstr.len == 0) { @@ -970,6 +975,8 @@ static const char *f2fs_encrypted_follow_link(struct dentry *dentry, void **cook if (res < 0) goto errout; + kfree(cstr.name); + paddr = pstr.name; /* Null-terminate the name */ @@ -979,6 +986,7 @@ static const char *f2fs_encrypted_follow_link(struct dentry *dentry, void **cook page_cache_release(cpage); return *cookie = paddr; errout: + kfree(cstr.name); f2fs_fname_crypto_free_buffer(&pstr); kunmap(cpage); page_cache_release(cpage); -- 2.1.1