From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 DB89B33B951; Thu, 2 Jul 2026 17:00:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783011608; cv=none; b=YtxgjE8KyWmv2Dnvaluj7vjDVHJBuTypE/W6s5r6llgy9c/8xOXICtNo4mESI6LqNxuPVG5Yg917LBe44toGHOMte37TrEt8SlUFIUoBBV9h4BssosSaG7h2bD0nokXLi8NHl6tS19LN26XgmDkZDfUyySaPyI7qcthlpg/UAIg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783011608; c=relaxed/simple; bh=mkcDbWIUss9K/caYdLVTPe39XBOnGklBioEft7G0nhA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eAJeP+hqpbbLvHahj4vim6Gt+6lA3oBt4i4wd0Cf6+8WHEP4LdDmBecoVT1uRWGAAjh70uTfcY1lDAPZAevmCfXLzWACT+Ed78fUObmSiTYw+MGJZ0vFavrS+Jv+5NuWfd980a2H5fSUpGm/iFcEu992IO8ucPZq8CJNcgBAdRQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZDNWuqsO; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ZDNWuqsO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4CC421F00A3E; Thu, 2 Jul 2026 17:00:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1783011606; bh=QtaPiGDHeCpZ7glIn7ByaGfNEWrI25TpxJ0WN9J/1wk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ZDNWuqsO0uiSpHKnhiDkhgD7akU8W8sP0plh7x448ZUhy8iR7zSZSSFuyuX/Hf8J6 sZUl5KEZZ7Xt1LbwNtR7bphiX8+RdHnMKeUWz3qYz09k4ZEWeYDBBE1GAeFo0MuB5z bRjf03nOBEBSDwd0k8Uon+uDT/aNMzaWOp4hkr5o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable@kernel.org, Daeho Jeong , Sunmin Jeong , Chao Yu , Jaegeuk Kim Subject: [PATCH 7.1 065/120] f2fs: atomic: fix UAF issue on f2fs_inode_info.atomic_inode Date: Thu, 2 Jul 2026 18:21:01 +0200 Message-ID: <20260702155114.304061913@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260702155112.964534952@linuxfoundation.org> References: <20260702155112.964534952@linuxfoundation.org> User-Agent: quilt/0.69 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 7.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chao Yu commit e0288584baa5dc41df4a829a023c4c1b33fe53d7 upstream. - ioctl(F2FS_IOC_GARBAGE_COLLECT_RANGE) - shrink - f2fs_gc - gc_data_segment - ra_data_block(cow_inode) - mapping = F2FS_I(inode)->atomic_inode->i_mapping : f2fs_is_cow_file(cow_inode) is true - f2fs_evict_inode(atomic_inode) - clear_inode_flag(fi->cow_inode, FI_COW_FILE) - F2FS_I(fi->cow_inode)->atomic_inode = NULL ... - truncate_inode_pages_final(atomic_inode) - f2fs_grab_cache_folio(mapping) : create folio in atomic_inode->mapping - clear_inode(atomic_inode) - BUG_ON(atomic_inode->i_data.nrpages) We need to add a reference on fi->atomic_inode before using its mapping field during garbage collection, otherwise, it will cause UAF issue. Cc: stable@kernel.org Cc: Daeho Jeong Cc: Sunmin Jeong Fixes: 3db1de0e582c ("f2fs: change the current atomic write way") Fixes: f18d00769336 ("f2fs: use meta inode for GC of COW file") Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/gc.c | 50 ++++++++++++++++++++++++++++++++++++++++++-------- fs/f2fs/inode.c | 11 ++++++++--- 2 files changed, 50 insertions(+), 11 deletions(-) --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -1220,8 +1220,8 @@ static bool is_alive(struct f2fs_sb_info static int ra_data_block(struct inode *inode, pgoff_t index) { struct f2fs_sb_info *sbi = F2FS_I_SB(inode); - struct address_space *mapping = f2fs_is_cow_file(inode) ? - F2FS_I(inode)->atomic_inode->i_mapping : inode->i_mapping; + struct address_space *mapping = inode->i_mapping; + struct inode *atomic_inode = NULL; struct dnode_of_data dn; struct folio *folio, *efolio; struct f2fs_io_info fio = { @@ -1236,9 +1236,22 @@ static int ra_data_block(struct inode *i }; int err = 0; + f2fs_down_read(&F2FS_I(inode)->i_sem); + if (f2fs_is_cow_file(inode)) { + atomic_inode = igrab(F2FS_I(inode)->atomic_inode); + if (!atomic_inode) { + f2fs_up_read(&F2FS_I(inode)->i_sem); + return -EBUSY; + } + mapping = atomic_inode->i_mapping; + } + f2fs_up_read(&F2FS_I(inode)->i_sem); + folio = f2fs_grab_cache_folio(mapping, index, true); - if (IS_ERR(folio)) - return PTR_ERR(folio); + if (IS_ERR(folio)) { + err = PTR_ERR(folio); + goto out_iput; + } if (f2fs_lookup_read_extent_cache_block(inode, index, &dn.data_blkaddr)) { @@ -1299,11 +1312,16 @@ got_it: f2fs_update_iostat(sbi, inode, FS_DATA_READ_IO, F2FS_BLKSIZE); f2fs_update_iostat(sbi, NULL, FS_GDATA_READ_IO, F2FS_BLKSIZE); + if (atomic_inode) + iput(atomic_inode); return 0; put_encrypted_page: f2fs_put_page(fio.encrypted_page, true); put_folio: f2fs_folio_put(folio, true); +out_iput: + if (atomic_inode) + iput(atomic_inode); return err; } @@ -1314,8 +1332,8 @@ put_folio: static int move_data_block(struct inode *inode, block_t bidx, int gc_type, unsigned int segno, int off) { - struct address_space *mapping = f2fs_is_cow_file(inode) ? - F2FS_I(inode)->atomic_inode->i_mapping : inode->i_mapping; + struct address_space *mapping = inode->i_mapping; + struct inode *atomic_inode = NULL; struct f2fs_io_info fio = { .sbi = F2FS_I_SB(inode), .ino = inode->i_ino, @@ -1337,10 +1355,23 @@ static int move_data_block(struct inode (fio.sbi->gc_mode != GC_URGENT_HIGH) ? CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA; + f2fs_down_read(&F2FS_I(inode)->i_sem); + if (f2fs_is_cow_file(inode)) { + atomic_inode = igrab(F2FS_I(inode)->atomic_inode); + if (!atomic_inode) { + f2fs_up_read(&F2FS_I(inode)->i_sem); + return -EBUSY; + } + mapping = atomic_inode->i_mapping; + } + f2fs_up_read(&F2FS_I(inode)->i_sem); + /* do not read out */ folio = f2fs_grab_cache_folio(mapping, bidx, false); - if (IS_ERR(folio)) - return PTR_ERR(folio); + if (IS_ERR(folio)) { + err = PTR_ERR(folio); + goto out_iput; + } if (!check_valid_map(F2FS_I_SB(inode), segno, off)) { err = -ENOENT; @@ -1473,6 +1504,9 @@ out: folio_unlock(folio); folio_end_dropbehind(folio); folio_put(folio); +out_iput: + if (atomic_inode) + iput(atomic_inode); return err; } --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -863,10 +863,15 @@ void f2fs_evict_inode(struct inode *inod f2fs_abort_atomic_write(inode, true); if (fi->cow_inode && f2fs_is_cow_file(fi->cow_inode)) { - clear_inode_flag(fi->cow_inode, FI_COW_FILE); - F2FS_I(fi->cow_inode)->atomic_inode = NULL; - iput(fi->cow_inode); + struct inode *cow_inode = fi->cow_inode; + + f2fs_down_write(&F2FS_I(cow_inode)->i_sem); + clear_inode_flag(cow_inode, FI_COW_FILE); + F2FS_I(cow_inode)->atomic_inode = NULL; fi->cow_inode = NULL; + f2fs_up_write(&F2FS_I(cow_inode)->i_sem); + + iput(cow_inode); } trace_f2fs_evict_inode(inode);