From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753497AbbIOQwT (ORCPT ); Tue, 15 Sep 2015 12:52:19 -0400 Received: from mail.kernel.org ([198.145.29.136]:33246 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752312AbbIOQwP (ORCPT ); Tue, 15 Sep 2015 12:52:15 -0400 Date: Tue, 15 Sep 2015 09:52:15 -0700 From: Jaegeuk Kim To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Cc: stable@vger.kernel.org Subject: Re: [f2fs-dev] [PATCH v3] f2fs crypto: allocate buffer for decrypting filename Message-ID: <20150915165215.GA82346@jaegeuk-mac02.mot.com> References: <1441936062-69511-1-git-send-email-jaegeuk@kernel.org> <20150911224550.GA73045@jaegeuk-mac02.mot.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150911224550.GA73045@jaegeuk-mac02.mot.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 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 84574dd5c3e8ed9ca9fdfcbd251b354cdbc5ecab Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Thu, 3 Sep 2015 13:38:23 -0700 Subject: [PATCH 1/3] 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 | 14 +++++++++++--- fs/f2fs/namei.c | 8 +++++++- 2 files changed, 18 insertions(+), 4 deletions(-) diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index 8f15fc1..cce512c 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -773,6 +773,7 @@ bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, unsigned int bit_pos; struct f2fs_dir_entry *de = NULL; struct f2fs_str de_name = FSTR_INIT(NULL, 0); + char *name = NULL; bit_pos = ((unsigned long)ctx->pos % d->max); @@ -788,8 +789,10 @@ bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, d_type = DT_UNKNOWN; /* encrypted case */ - de_name.name = d->filename[bit_pos]; de_name.len = le16_to_cpu(de->name_len); + name = kmalloc(de_name.len, GFP_NOFS); + memcpy(name, d->filename[bit_pos], de_name.len); + de_name.name = name; if (f2fs_encrypted_inode(d->inode)) { int save_len = fstr->len; @@ -799,13 +802,18 @@ bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, &de_name, fstr); de_name = *fstr; fstr->len = save_len; - if (ret < 0) + if (ret < 0) { + kfree(name); return true; + } } if (!dir_emit(ctx, de_name.name, de_name.len, - le32_to_cpu(de->ino), d_type)) + le32_to_cpu(de->ino), d_type)) { + kfree(name); return true; + } + kfree(name); bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); ctx->pos = start_pos + bit_pos; diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c index a680bf3..ebd612e 100644 --- a/fs/f2fs/namei.c +++ b/fs/f2fs/namei.c @@ -933,6 +933,7 @@ static const char *f2fs_encrypted_follow_link(struct dentry *dentry, void **cook struct f2fs_encrypted_symlink_data *sd; loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1); u32 max_size = inode->i_sb->s_blocksize; + char *name = NULL; int res; res = f2fs_get_encryption_info(inode); @@ -947,8 +948,10 @@ 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); + name = kmalloc(cstr.len, GFP_NOFS); + memcpy(name, sd->encrypted_path, cstr.len); + cstr.name = name; /* this is broken symlink case */ if (cstr.name[0] == 0 && cstr.len == 0) { @@ -970,6 +973,8 @@ static const char *f2fs_encrypted_follow_link(struct dentry *dentry, void **cook if (res < 0) goto errout; + kfree(name); + paddr = pstr.name; /* Null-terminate the name */ @@ -979,6 +984,7 @@ static const char *f2fs_encrypted_follow_link(struct dentry *dentry, void **cook page_cache_release(cpage); return *cookie = paddr; errout: + kfree(name); f2fs_fname_crypto_free_buffer(&pstr); kunmap(cpage); page_cache_release(cpage); -- 2.1.1