From: Chao Yu chao@kernel.org
commit a6ec83786ab9f13f25fb18166dee908845713a95 upstream.
syzbot reports below bug:
BUG: KASAN: slab-use-after-free in f2fs_truncate_data_blocks_range+0x122a/0x14c0 fs/f2fs/file.c:574 Read of size 4 at addr ffff88802a25c000 by task syz-executor148/5000
CPU: 1 PID: 5000 Comm: syz-executor148 Not tainted 6.4.0-rc7-syzkaller-00041-ge660abd551f1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:351 print_report mm/kasan/report.c:462 [inline] kasan_report+0x11c/0x130 mm/kasan/report.c:572 f2fs_truncate_data_blocks_range+0x122a/0x14c0 fs/f2fs/file.c:574 truncate_dnode+0x229/0x2e0 fs/f2fs/node.c:944 f2fs_truncate_inode_blocks+0x64b/0xde0 fs/f2fs/node.c:1154 f2fs_do_truncate_blocks+0x4ac/0xf30 fs/f2fs/file.c:721 f2fs_truncate_blocks+0x7b/0x300 fs/f2fs/file.c:749 f2fs_truncate.part.0+0x4a5/0x630 fs/f2fs/file.c:799 f2fs_truncate include/linux/fs.h:825 [inline] f2fs_setattr+0x1738/0x2090 fs/f2fs/file.c:1006 notify_change+0xb2c/0x1180 fs/attr.c:483 do_truncate+0x143/0x200 fs/open.c:66 handle_truncate fs/namei.c:3295 [inline] do_open fs/namei.c:3640 [inline] path_openat+0x2083/0x2750 fs/namei.c:3791 do_filp_open+0x1ba/0x410 fs/namei.c:3818 do_sys_openat2+0x16d/0x4c0 fs/open.c:1356 do_sys_open fs/open.c:1372 [inline] __do_sys_creat fs/open.c:1448 [inline] __se_sys_creat fs/open.c:1442 [inline] __x64_sys_creat+0xcd/0x120 fs/open.c:1442 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd
The root cause is, inodeA references inodeB via inodeB's ino, once inodeA is truncated, it calls truncate_dnode() to truncate data blocks in inodeB's node page, it traverse mapping data from node->i.i_addr[0] to node->i.i_addr[ADDRS_PER_BLOCK() - 1], result in out-of-boundary access.
This patch fixes to add sanity check on dnode page in truncate_dnode(), so that, it can help to avoid triggering such issue, and once it encounters such issue, it will record newly introduced ERROR_INVALID_NODE_REFERENCE error into superblock, later fsck can detect such issue and try repairing.
Also, it removes f2fs_truncate_data_blocks() for cleanup due to the function has only one caller, and uses f2fs_truncate_data_blocks_range() instead.
Reported-and-tested-by: syzbot+12cb4425b22169b52036@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-f2fs-devel/000000000000f3038a05fef867f8@google... Signed-off-by: Chao Yu chao@kernel.org Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/f2fs/f2fs.h | 1 - fs/f2fs/file.c | 5 ----- fs/f2fs/node.c | 14 ++++++++++++-- include/linux/f2fs_fs.h | 1 + 4 files changed, 13 insertions(+), 8 deletions(-)
--- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -3431,7 +3431,6 @@ static inline bool __is_valid_data_blkad * file.c */ int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync); -void f2fs_truncate_data_blocks(struct dnode_of_data *dn); int f2fs_do_truncate_blocks(struct inode *inode, u64 from, bool lock); int f2fs_truncate_blocks(struct inode *inode, u64 from, bool lock); int f2fs_truncate(struct inode *inode); --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -628,11 +628,6 @@ void f2fs_truncate_data_blocks_range(str dn->ofs_in_node, nr_free); }
-void f2fs_truncate_data_blocks(struct dnode_of_data *dn) -{ - f2fs_truncate_data_blocks_range(dn, ADDRS_PER_BLOCK(dn->inode)); -} - static int truncate_partial_data_page(struct inode *inode, u64 from, bool cache_only) { --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -923,6 +923,7 @@ static int truncate_node(struct dnode_of
static int truncate_dnode(struct dnode_of_data *dn) { + struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode); struct page *page; int err;
@@ -930,16 +931,25 @@ static int truncate_dnode(struct dnode_o return 1;
/* get direct node */ - page = f2fs_get_node_page(F2FS_I_SB(dn->inode), dn->nid); + page = f2fs_get_node_page(sbi, dn->nid); if (PTR_ERR(page) == -ENOENT) return 1; else if (IS_ERR(page)) return PTR_ERR(page);
+ if (IS_INODE(page) || ino_of_node(page) != dn->inode->i_ino) { + f2fs_err(sbi, "incorrect node reference, ino: %lu, nid: %u, ino_of_node: %u", + dn->inode->i_ino, dn->nid, ino_of_node(page)); + set_sbi_flag(sbi, SBI_NEED_FSCK); + f2fs_handle_error(sbi, ERROR_INVALID_NODE_REFERENCE); + f2fs_put_page(page, 1); + return -EFSCORRUPTED; + } + /* Make dnode_of_data for parameter */ dn->node_page = page; dn->ofs_in_node = 0; - f2fs_truncate_data_blocks(dn); + f2fs_truncate_data_blocks_range(dn, ADDRS_PER_BLOCK(dn->inode)); err = truncate_node(dn); if (err) { f2fs_put_page(page, 1); --- a/include/linux/f2fs_fs.h +++ b/include/linux/f2fs_fs.h @@ -104,6 +104,7 @@ enum f2fs_error { ERROR_INCONSISTENT_SIT, ERROR_CORRUPTED_VERITY_XATTR, ERROR_CORRUPTED_XATTR, + ERROR_INVALID_NODE_REFERENCE, ERROR_MAX, };