kernel/linux.git/fs/hfs, branch v6.1.168

hfs: fix KMSAN uninit-value issue in hfs_find_set_zero_bits()

2025-10-29T13:04:36+00:00

[ Upstream commit 2048ec5b98dbdfe0b929d2e42dc7a54c389c53dd ] The syzbot reported issue in hfs_find_set_zero_bits(): ===================================================== BUG: KMSAN: uninit-value in hfs_find_set_zero_bits+0x74d/0xb60 fs/hfs/bitmap.c:45 hfs_find_set_zero_bits+0x74d/0xb60 fs/hfs/bitmap.c:45 hfs_vbm_search_free+0x13c/0x5b0 fs/hfs/bitmap.c:151 hfs_extend_file+0x6a5/0x1b00 fs/hfs/extent.c:408 hfs_get_block+0x435/0x1150 fs/hfs/extent.c:353 __block_write_begin_int+0xa76/0x3030 fs/buffer.c:2151 block_write_begin fs/buffer.c:2262 [inline] cont_write_begin+0x10e1/0x1bc0 fs/buffer.c:2601 hfs_write_begin+0x85/0x130 fs/hfs/inode.c:52 cont_expand_zero fs/buffer.c:2528 [inline] cont_write_begin+0x35a/0x1bc0 fs/buffer.c:2591 hfs_write_begin+0x85/0x130 fs/hfs/inode.c:52 hfs_file_truncate+0x1d6/0xe60 fs/hfs/extent.c:494 hfs_inode_setattr+0x964/0xaa0 fs/hfs/inode.c:654 notify_change+0x1993/0x1aa0 fs/attr.c:552 do_truncate+0x28f/0x310 fs/open.c:68 do_ftruncate+0x698/0x730 fs/open.c:195 do_sys_ftruncate fs/open.c:210 [inline] __do_sys_ftruncate fs/open.c:215 [inline] __se_sys_ftruncate fs/open.c:213 [inline] __x64_sys_ftruncate+0x11b/0x250 fs/open.c:213 x64_sys_call+0xfe3/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:78 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was created at: slab_post_alloc_hook mm/slub.c:4154 [inline] slab_alloc_node mm/slub.c:4197 [inline] __kmalloc_cache_noprof+0x7f7/0xed0 mm/slub.c:4354 kmalloc_noprof include/linux/slab.h:905 [inline] hfs_mdb_get+0x1cc8/0x2a90 fs/hfs/mdb.c:175 hfs_fill_super+0x3d0/0xb80 fs/hfs/super.c:337 get_tree_bdev_flags+0x6e3/0x920 fs/super.c:1681 get_tree_bdev+0x38/0x50 fs/super.c:1704 hfs_get_tree+0x35/0x40 fs/hfs/super.c:388 vfs_get_tree+0xb0/0x5c0 fs/super.c:1804 do_new_mount+0x738/0x1610 fs/namespace.c:3902 path_mount+0x6db/0x1e90 fs/namespace.c:4226 do_mount fs/namespace.c:4239 [inline] __do_sys_mount fs/namespace.c:4450 [inline] __se_sys_mount+0x6eb/0x7d0 fs/namespace.c:4427 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4427 x64_sys_call+0xfa7/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f CPU: 1 UID: 0 PID: 12609 Comm: syz.1.2692 Not tainted 6.16.0-syzkaller #0 PREEMPT(none) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 ===================================================== The HFS_SB(sb)->bitmap buffer is allocated in hfs_mdb_get(): HFS_SB(sb)->bitmap = kmalloc(8192, GFP_KERNEL); Finally, it can trigger the reported issue because kmalloc() doesn't clear the allocated memory. If allocated memory contains only zeros, then everything will work pretty fine. But if the allocated memory contains the "garbage", then it can affect the bitmap operations and it triggers the reported issue. This patch simply exchanges the kmalloc() on kzalloc() with the goal to guarantee the correctness of bitmap operations. Because, newly created allocation bitmap should have all available blocks free. Potentially, initialization bitmap's read operation could not fill the whole allocated memory and "garbage" in the not initialized memory will be the reason of volume coruptions and file system driver bugs. Reported-by: syzbot Closes: https://syzkaller.appspot.com/bug?extid=773fa9d79b29bd8b6831 Signed-off-by: Viacheslav Dubeyko cc: John Paul Adrian Glaubitz cc: Yangtao Li cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20250820230636.179085-1-slava@dubeyko.com Signed-off-by: Viacheslav Dubeyko Signed-off-by: Sasha Levin

hfs: make proper initalization of struct hfs_find_data

2025-10-29T13:04:35+00:00

[ Upstream commit c62663a986acee7c4485c1fa9de5fc40194b6290 ] Potenatially, __hfs_ext_read_extent() could operate by not initialized values of fd->key after hfs_brec_find() call: static inline int __hfs_ext_read_extent(struct hfs_find_data *fd, struct hfs_extent *extent, u32 cnid, u32 block, u8 type) { int res; hfs_ext_build_key(fd->search_key, cnid, block, type); fd->key->ext.FNum = 0; res = hfs_brec_find(fd); if (res && res != -ENOENT) return res; if (fd->key->ext.FNum != fd->search_key->ext.FNum || fd->key->ext.FkType != fd->search_key->ext.FkType) return -ENOENT; if (fd->entrylength != sizeof(hfs_extent_rec)) return -EIO; hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfs_extent_rec)); return 0; } This patch changes kmalloc() on kzalloc() in hfs_find_init() and intializes fd->record, fd->keyoffset, fd->keylength, fd->entryoffset, fd->entrylength for the case if hfs_brec_find() has been found nothing in the b-tree node. Signed-off-by: Viacheslav Dubeyko cc: John Paul Adrian Glaubitz cc: Yangtao Li cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20250818225252.126427-1-slava@dubeyko.com Signed-off-by: Viacheslav Dubeyko Signed-off-by: Sasha Levin

hfs: clear offset and space out of valid records in b-tree node

2025-10-29T13:04:35+00:00

[ Upstream commit 18b07c44f245beb03588b00b212b38fce9af7cc9 ] Currently, hfs_brec_remove() executes moving records towards the location of deleted record and it updates offsets of moved records. However, the hfs_brec_remove() logic ignores the "mess" of b-tree node's free space and it doesn't touch the offsets out of records number. Potentially, it could confuse fsck or driver logic or to be a reason of potential corruption cases. This patch reworks the logic of hfs_brec_remove() by means of clearing freed space of b-tree node after the records moving. And it clear the last offset that keeping old location of free space because now the offset before this one is keeping the actual offset to the free space after the record deletion. Signed-off-by: Viacheslav Dubeyko cc: John Paul Adrian Glaubitz cc: Yangtao Li cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20250815194918.38165-1-slava@dubeyko.com Signed-off-by: Viacheslav Dubeyko Signed-off-by: Sasha Levin

hfs: fix not erasing deleted b-tree node issue

2025-08-28T14:25:51+00:00

[ Upstream commit d3ed6d6981f4756f145766753c872482bc3b28d3 ] The generic/001 test of xfstests suite fails and corrupts the HFS volume: sudo ./check generic/001 FSTYP -- hfs PLATFORM -- Linux/x86_64 hfsplus-testing-0001 6.15.0-rc2+ #3 SMP PREEMPT_DYNAMIC Fri Apr 25 17:13:00 PDT 2> MKFS_OPTIONS -- /dev/loop51 MOUNT_OPTIONS -- /dev/loop51 /mnt/scratch generic/001 32s ... _check_generic_filesystem: filesystem on /dev/loop50 is inconsistent (see /home/slavad/XFSTESTS-2/xfstests-dev/results//generic/001.full for details) Ran: generic/001 Failures: generic/001 Failed 1 of 1 tests fsck.hfs -d -n ./test-image.bin ** ./test-image.bin (NO WRITE) Using cacheBlockSize=32K cacheTotalBlock=1024 cacheSize=32768K. Executing fsck_hfs (version 540.1-Linux). ** Checking HFS volume. The volume name is untitled ** Checking extents overflow file. ** Checking catalog file. Unused node is not erased (node = 2) Unused node is not erased (node = 4) Unused node is not erased (node = 253) Unused node is not erased (node = 254) Unused node is not erased (node = 255) Unused node is not erased (node = 256) ** Checking catalog hierarchy. ** Checking volume bitmap. ** Checking volume information. Verify Status: VIStat = 0x0000, ABTStat = 0x0000 EBTStat = 0x0000 CBTStat = 0x0004 CatStat = 0x00000000 ** The volume untitled was found corrupt and needs to be repaired. volume type is HFS primary MDB is at block 2 0x02 alternate MDB is at block 20971518 0x13ffffe primary VHB is at block 0 0x00 alternate VHB is at block 0 0x00 sector size = 512 0x200 VolumeObject flags = 0x19 total sectors for volume = 20971520 0x1400000 total sectors for embedded volume = 0 0x00 This patch adds logic of clearing the deleted b-tree node. sudo ./check generic/001 FSTYP -- hfs PLATFORM -- Linux/x86_64 hfsplus-testing-0001 6.15.0-rc2+ #3 SMP PREEMPT_DYNAMIC Fri Apr 25 17:13:00 PDT 2025 MKFS_OPTIONS -- /dev/loop51 MOUNT_OPTIONS -- /dev/loop51 /mnt/scratch generic/001 9s ... 32s Ran: generic/001 Passed all 1 tests fsck.hfs -d -n ./test-image.bin ** ./test-image.bin (NO WRITE) Using cacheBlockSize=32K cacheTotalBlock=1024 cacheSize=32768K. Executing fsck_hfs (version 540.1-Linux). ** Checking HFS volume. The volume name is untitled ** Checking extents overflow file. ** Checking catalog file. ** Checking catalog hierarchy. ** Checking volume bitmap. ** Checking volume information. ** The volume untitled appears to be OK. Signed-off-by: Viacheslav Dubeyko Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20250430001211.1912533-1-slava@dubeyko.com Signed-off-by: Viacheslav Dubeyko Signed-off-by: Sasha Levin

hfs: fix slab-out-of-bounds in hfs_bnode_read()

2025-08-28T14:25:51+00:00

[ Upstream commit a431930c9bac518bf99d6b1da526a7f37ddee8d8 ] This patch introduces is_bnode_offset_valid() method that checks the requested offset value. Also, it introduces check_and_correct_requested_length() method that checks and correct the requested length (if it is necessary). These methods are used in hfs_bnode_read(), hfs_bnode_write(), hfs_bnode_clear(), hfs_bnode_copy(), and hfs_bnode_move() with the goal to prevent the access out of allocated memory and triggering the crash. Signed-off-by: Viacheslav Dubeyko Link: https://lore.kernel.org/r/20250703214912.244138-1-slava@dubeyko.com Signed-off-by: Viacheslav Dubeyko Signed-off-by: Sasha Levin

hfs/hfsplus: fix slab-out-of-bounds in hfs_bnode_read_key

2025-04-25T08:43:53+00:00

commit bb5e07cb927724e0b47be371fa081141cfb14414 upstream. Syzbot reported an issue in hfs subsystem: BUG: KASAN: slab-out-of-bounds in memcpy_from_page include/linux/highmem.h:423 [inline] BUG: KASAN: slab-out-of-bounds in hfs_bnode_read fs/hfs/bnode.c:35 [inline] BUG: KASAN: slab-out-of-bounds in hfs_bnode_read_key+0x314/0x450 fs/hfs/bnode.c:70 Write of size 94 at addr ffff8880123cd100 by task syz-executor237/5102 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 __asan_memcpy+0x40/0x70 mm/kasan/shadow.c:106 memcpy_from_page include/linux/highmem.h:423 [inline] hfs_bnode_read fs/hfs/bnode.c:35 [inline] hfs_bnode_read_key+0x314/0x450 fs/hfs/bnode.c:70 hfs_brec_insert+0x7f3/0xbd0 fs/hfs/brec.c:159 hfs_cat_create+0x41d/0xa50 fs/hfs/catalog.c:118 hfs_mkdir+0x6c/0xe0 fs/hfs/dir.c:232 vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257 do_mkdirat+0x264/0x3a0 fs/namei.c:4280 __do_sys_mkdir fs/namei.c:4300 [inline] __se_sys_mkdir fs/namei.c:4298 [inline] __x64_sys_mkdir+0x6c/0x80 fs/namei.c:4298 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbdd6057a99 Add a check for key length in hfs_bnode_read_key to prevent out-of-bounds memory access. If the key length is invalid, the key buffer is cleared, improving stability and reliability. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+5f3a973ed3dfb85a6683@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=5f3a973ed3dfb85a6683 Cc: stable@vger.kernel.org Signed-off-by: Vasiliy Kovalev Link: https://lore.kernel.org/20241019191303.24048-1-kovalev@altlinux.org Reviewed-by: Cengiz Can Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman

hfs: Sanity check the root record

2025-01-23T16:17:11+00:00

[ Upstream commit b905bafdea21a75d75a96855edd9e0b6051eee30 ] In the syzbot reproducer, the hfs_cat_rec for the root dir has type HFS_CDR_FIL after being read with hfs_bnode_read() in hfs_super_fill(). This indicates it should be used as an hfs_cat_file, which is 102 bytes. Only the first 70 bytes of that struct are initialized, however, because the entrylength passed into hfs_bnode_read() is still the length of a directory record. This causes uninitialized values to be used later on, when the hfs_cat_rec union is treated as the larger hfs_cat_file struct. Add a check to make sure the retrieved record has the correct type for the root directory (HFS_CDR_DIR), and make sure we load the correct number of bytes for a directory record. Reported-by: syzbot+2db3c7526ba68f4ea776@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=2db3c7526ba68f4ea776 Tested-by: syzbot+2db3c7526ba68f4ea776@syzkaller.appspotmail.com Tested-by: Leo Stone Signed-off-by: Leo Stone Link: https://lore.kernel.org/r/20241201051420.77858-1-leocstone@gmail.com Reviewed-by: Jan Kara Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

hfs: fix to initialize fields of hfs_inode_info after hfs_alloc_inode()

2024-08-03T06:49:32+00:00

commit 26a2ed107929a855155429b11e1293b83e6b2a8b upstream. Syzbot reports uninitialized value access issue as below: loop0: detected capacity change from 0 to 64 ===================================================== BUG: KMSAN: uninit-value in hfs_revalidate_dentry+0x307/0x3f0 fs/hfs/sysdep.c:30 hfs_revalidate_dentry+0x307/0x3f0 fs/hfs/sysdep.c:30 d_revalidate fs/namei.c:862 [inline] lookup_fast+0x89e/0x8e0 fs/namei.c:1649 walk_component fs/namei.c:2001 [inline] link_path_walk+0x817/0x1480 fs/namei.c:2332 path_lookupat+0xd9/0x6f0 fs/namei.c:2485 filename_lookup+0x22e/0x740 fs/namei.c:2515 user_path_at_empty+0x8b/0x390 fs/namei.c:2924 user_path_at include/linux/namei.h:57 [inline] do_mount fs/namespace.c:3689 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x66b/0x810 fs/namespace.c:3875 __x64_sys_mount+0xe4/0x140 fs/namespace.c:3875 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b BUG: KMSAN: uninit-value in hfs_ext_read_extent fs/hfs/extent.c:196 [inline] BUG: KMSAN: uninit-value in hfs_get_block+0x92d/0x1620 fs/hfs/extent.c:366 hfs_ext_read_extent fs/hfs/extent.c:196 [inline] hfs_get_block+0x92d/0x1620 fs/hfs/extent.c:366 block_read_full_folio+0x4ff/0x11b0 fs/buffer.c:2271 hfs_read_folio+0x55/0x60 fs/hfs/inode.c:39 filemap_read_folio+0x148/0x4f0 mm/filemap.c:2426 do_read_cache_folio+0x7c8/0xd90 mm/filemap.c:3553 do_read_cache_page mm/filemap.c:3595 [inline] read_cache_page+0xfb/0x2f0 mm/filemap.c:3604 read_mapping_page include/linux/pagemap.h:755 [inline] hfs_btree_open+0x928/0x1ae0 fs/hfs/btree.c:78 hfs_mdb_get+0x260c/0x3000 fs/hfs/mdb.c:204 hfs_fill_super+0x1fb1/0x2790 fs/hfs/super.c:406 mount_bdev+0x628/0x920 fs/super.c:1359 hfs_mount+0xcd/0xe0 fs/hfs/super.c:456 legacy_get_tree+0x167/0x2e0 fs/fs_context.c:610 vfs_get_tree+0xdc/0x5d0 fs/super.c:1489 do_new_mount+0x7a9/0x16f0 fs/namespace.c:3145 path_mount+0xf98/0x26a0 fs/namespace.c:3475 do_mount fs/namespace.c:3488 [inline] __do_sys_mount fs/namespace.c:3697 [inline] __se_sys_mount+0x919/0x9e0 fs/namespace.c:3674 __ia32_sys_mount+0x15b/0x1b0 fs/namespace.c:3674 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178 do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Uninit was created at: __alloc_pages+0x9a6/0xe00 mm/page_alloc.c:4590 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page mm/slub.c:2190 [inline] allocate_slab mm/slub.c:2354 [inline] new_slab+0x2d7/0x1400 mm/slub.c:2407 ___slab_alloc+0x16b5/0x3970 mm/slub.c:3540 __slab_alloc mm/slub.c:3625 [inline] __slab_alloc_node mm/slub.c:3678 [inline] slab_alloc_node mm/slub.c:3850 [inline] kmem_cache_alloc_lru+0x64d/0xb30 mm/slub.c:3879 alloc_inode_sb include/linux/fs.h:3018 [inline] hfs_alloc_inode+0x5a/0xc0 fs/hfs/super.c:165 alloc_inode+0x83/0x440 fs/inode.c:260 new_inode_pseudo fs/inode.c:1005 [inline] new_inode+0x38/0x4f0 fs/inode.c:1031 hfs_new_inode+0x61/0x1010 fs/hfs/inode.c:186 hfs_mkdir+0x54/0x250 fs/hfs/dir.c:228 vfs_mkdir+0x49a/0x700 fs/namei.c:4126 do_mkdirat+0x529/0x810 fs/namei.c:4149 __do_sys_mkdirat fs/namei.c:4164 [inline] __se_sys_mkdirat fs/namei.c:4162 [inline] __x64_sys_mkdirat+0xc8/0x120 fs/namei.c:4162 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b It missed to initialize .tz_secondswest, .cached_start and .cached_blocks fields in struct hfs_inode_info after hfs_alloc_inode(), fix it. Cc: stable@vger.kernel.org Reported-by: syzbot+3ae6be33a50b5aae4dab@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-fsdevel/0000000000005ad04005ee48897f@google.com Signed-off-by: Chao Yu Link: https://lore.kernel.org/r/20240616013841.2217-1-chao@kernel.org Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman

hfs: fix missing hfs_bnode_get() in __hfs_bnode_create

2023-03-10T08:34:07+00:00

commit a9dc087fd3c484fd1ed18c5efb290efaaf44ce03 upstream. Syzbot found a kernel BUG in hfs_bnode_put(): kernel BUG at fs/hfs/bnode.c:466! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 3634 Comm: kworker/u4:5 Not tainted 6.1.0-rc7-syzkaller-00190-g97ee9d1c1696 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:hfs_bnode_put+0x46f/0x480 fs/hfs/bnode.c:466 Code: 8a 80 ff e9 73 fe ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c a0 fe ff ff 48 89 df e8 db 8a 80 ff e9 93 fe ff ff e8 a1 68 2c ff <0f> 0b e8 9a 68 2c ff 0f 0b 0f 1f 84 00 00 00 00 00 55 41 57 41 56 RSP: 0018:ffffc90003b4f258 EFLAGS: 00010293 RAX: ffffffff825e318f RBX: 0000000000000000 RCX: ffff8880739dd7c0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003b4f430 R08: ffffffff825e2d9b R09: ffffed10045157d1 R10: ffffed10045157d1 R11: 1ffff110045157d0 R12: ffff8880228abe80 R13: ffff88807016c000 R14: dffffc0000000000 R15: ffff8880228abe00 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa6ebe88718 CR3: 000000001e93d000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: hfs_write_inode+0x1bc/0xb40 write_inode fs/fs-writeback.c:1440 [inline] __writeback_single_inode+0x4d6/0x670 fs/fs-writeback.c:1652 writeback_sb_inodes+0xb3b/0x18f0 fs/fs-writeback.c:1878 __writeback_inodes_wb+0x125/0x420 fs/fs-writeback.c:1949 wb_writeback+0x440/0x7b0 fs/fs-writeback.c:2054 wb_check_start_all fs/fs-writeback.c:2176 [inline] wb_do_writeback fs/fs-writeback.c:2202 [inline] wb_workfn+0x827/0xef0 fs/fs-writeback.c:2235 process_one_work+0x877/0xdb0 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 The BUG_ON() is triggered at here: /* Dispose of resources used by a node */ void hfs_bnode_put(struct hfs_bnode *node) { if (node) { BUG_ON(!atomic_read(&node->refcnt)); <- we have issue here!!!! } } By tracing the refcnt, I found the node is created by hfs_bmap_alloc() with refcnt 1. Then the node is used by hfs_btree_write(). There is a missing of hfs_bnode_get() after find the node. The issue happened in following path: hfs_bmap_alloc hfs_bnode_find __hfs_bnode_create <- allocate a new node with refcnt 1. hfs_bnode_put <- decrease the refcnt hfs_btree_write hfs_bnode_find __hfs_bnode_create hfs_bnode_findhash <- find the node without refcnt increased. hfs_bnode_put <- trigger the BUG_ON() since refcnt is 0. Link: https://lkml.kernel.org/r/20221212021627.3766829-1-liushixin2@huawei.com Reported-by: syzbot+5b04b49a7ec7226c7426@syzkaller.appspotmail.com Signed-off-by: Liu Shixin Cc: Fabio M. De Francesco Cc: Viacheslav Dubeyko Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

hfs/hfsplus: avoid WARN_ON() for sanity check, use proper error handling

2023-01-12T11:02:35+00:00

[ Upstream commit cb7a95af78d29442b8294683eca4897544b8ef46 ] Commit 55d1cbbbb29e ("hfs/hfsplus: use WARN_ON for sanity check") fixed a build warning by turning a comment into a WARN_ON(), but it turns out that syzbot then complains because it can trigger said warning with a corrupted hfs image. The warning actually does warn about a bad situation, but we are much better off just handling it as the error it is. So rather than warn about us doing bad things, stop doing the bad things and return -EIO. While at it, also fix a memory leak that was introduced by an earlier fix for a similar syzbot warning situation, and add a check for one case that historically wasn't handled at all (ie neither comment nor subsequent WARN_ON). Reported-by: syzbot+7bb7cd3595533513a9e7@syzkaller.appspotmail.com Fixes: 55d1cbbbb29e ("hfs/hfsplus: use WARN_ON for sanity check") Fixes: 8d824e69d9f3 ("hfs: fix OOB Read in __hfs_brec_find") Link: https://lore.kernel.org/lkml/000000000000dbce4e05f170f289@google.com/ Tested-by: Michael Schmitz Cc: Arnd Bergmann Cc: Matthew Wilcox Cc: Viacheslav Dubeyko Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin