From cd45e963e44b0f10d90b9e6c0e8b4f47f3c92471 Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Thu, 7 Nov 2024 01:07:32 +0900 Subject: nilfs2: fix null-ptr-deref in block_touch_buffer tracepoint Patch series "nilfs2: fix null-ptr-deref bugs on block tracepoints". This series fixes null pointer dereference bugs that occur when using nilfs2 and two block-related tracepoints. This patch (of 2): It has been reported that when using "block:block_touch_buffer" tracepoint, touch_buffer() called from __nilfs_get_folio_block() causes a NULL pointer dereference, or a general protection fault when KASAN is enabled. This happens because since the tracepoint was added in touch_buffer(), it references the dev_t member bh->b_bdev->bd_dev regardless of whether the buffer head has a pointer to a block_device structure. In the current implementation, the block_device structure is set after the function returns to the caller. Here, touch_buffer() is used to mark the folio/page that owns the buffer head as accessed, but the common search helper for folio/page used by the caller function was optimized to mark the folio/page as accessed when it was reimplemented a long time ago, eliminating the need to call touch_buffer() here in the first place. So this solves the issue by eliminating the touch_buffer() call itself. Link: https://lkml.kernel.org/r/20241106160811.3316-1-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/20241106160811.3316-2-konishi.ryusuke@gmail.com Fixes: 5305cb830834 ("block: add block_{touch|dirty}_buffer tracepoint") Signed-off-by: Ryusuke Konishi Reported-by: Ubisectech Sirius Closes: https://lkml.kernel.org/r/86bd3013-887e-4e38-960f-ca45c657f032.bugreport@valiantsec.com Reported-by: syzbot+9982fb8d18eba905abe2@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9982fb8d18eba905abe2 Tested-by: syzbot+9982fb8d18eba905abe2@syzkaller.appspotmail.com Cc: Tejun Heo Cc: Signed-off-by: Andrew Morton --- fs/nilfs2/page.c | 1 - 1 file changed, 1 deletion(-) (limited to 'fs') diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c index 10def4b55995..296dbf9cca22 100644 --- a/fs/nilfs2/page.c +++ b/fs/nilfs2/page.c @@ -39,7 +39,6 @@ static struct buffer_head *__nilfs_get_folio_block(struct folio *folio, first_block = (unsigned long)index << (PAGE_SHIFT - blkbits); bh = get_nth_bh(bh, block - first_block); - touch_buffer(bh); wait_on_buffer(bh); return bh; } -- cgit v1.2.3-73-gaa49b From 2026559a6c4ce34db117d2db8f710fe2a9420d5a Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Thu, 7 Nov 2024 01:07:33 +0900 Subject: nilfs2: fix null-ptr-deref in block_dirty_buffer tracepoint When using the "block:block_dirty_buffer" tracepoint, mark_buffer_dirty() may cause a NULL pointer dereference, or a general protection fault when KASAN is enabled. This happens because, since the tracepoint was added in mark_buffer_dirty(), it references the dev_t member bh->b_bdev->bd_dev regardless of whether the buffer head has a pointer to a block_device structure. In the current implementation, nilfs_grab_buffer(), which grabs a buffer to read (or create) a block of metadata, including b-tree node blocks, does not set the block device, but instead does so only if the buffer is not in the "uptodate" state for each of its caller block reading functions. However, if the uptodate flag is set on a folio/page, and the buffer heads are detached from it by try_to_free_buffers(), and new buffer heads are then attached by create_empty_buffers(), the uptodate flag may be restored to each buffer without the block device being set to bh->b_bdev, and mark_buffer_dirty() may be called later in that state, resulting in the bug mentioned above. Fix this issue by making nilfs_grab_buffer() always set the block device of the super block structure to the buffer head, regardless of the state of the buffer's uptodate flag. Link: https://lkml.kernel.org/r/20241106160811.3316-3-konishi.ryusuke@gmail.com Fixes: 5305cb830834 ("block: add block_{touch|dirty}_buffer tracepoint") Signed-off-by: Ryusuke Konishi Cc: Tejun Heo Cc: Ubisectech Sirius Cc: Signed-off-by: Andrew Morton --- fs/nilfs2/btnode.c | 2 -- fs/nilfs2/gcinode.c | 4 +--- fs/nilfs2/mdt.c | 1 - fs/nilfs2/page.c | 1 + 4 files changed, 2 insertions(+), 6 deletions(-) (limited to 'fs') diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c index 57b4af5ad646..501ad7be5174 100644 --- a/fs/nilfs2/btnode.c +++ b/fs/nilfs2/btnode.c @@ -68,7 +68,6 @@ nilfs_btnode_create_block(struct address_space *btnc, __u64 blocknr) goto failed; } memset(bh->b_data, 0, i_blocksize(inode)); - bh->b_bdev = inode->i_sb->s_bdev; bh->b_blocknr = blocknr; set_buffer_mapped(bh); set_buffer_uptodate(bh); @@ -133,7 +132,6 @@ int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr, goto found; } set_buffer_mapped(bh); - bh->b_bdev = inode->i_sb->s_bdev; bh->b_blocknr = pblocknr; /* set block address for read */ bh->b_end_io = end_buffer_read_sync; get_bh(bh); diff --git a/fs/nilfs2/gcinode.c b/fs/nilfs2/gcinode.c index 1c9ae36a03ab..ace22253fed0 100644 --- a/fs/nilfs2/gcinode.c +++ b/fs/nilfs2/gcinode.c @@ -83,10 +83,8 @@ int nilfs_gccache_submit_read_data(struct inode *inode, sector_t blkoff, goto out; } - if (!buffer_mapped(bh)) { - bh->b_bdev = inode->i_sb->s_bdev; + if (!buffer_mapped(bh)) set_buffer_mapped(bh); - } bh->b_blocknr = pbn; bh->b_end_io = end_buffer_read_sync; get_bh(bh); diff --git a/fs/nilfs2/mdt.c b/fs/nilfs2/mdt.c index ceb7dc0b5bad..2db6350b5ac2 100644 --- a/fs/nilfs2/mdt.c +++ b/fs/nilfs2/mdt.c @@ -89,7 +89,6 @@ static int nilfs_mdt_create_block(struct inode *inode, unsigned long block, if (buffer_uptodate(bh)) goto failed_bh; - bh->b_bdev = sb->s_bdev; err = nilfs_mdt_insert_new_block(inode, block, bh, init_block); if (likely(!err)) { get_bh(bh); diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c index 296dbf9cca22..6dd8b854cd1f 100644 --- a/fs/nilfs2/page.c +++ b/fs/nilfs2/page.c @@ -63,6 +63,7 @@ struct buffer_head *nilfs_grab_buffer(struct inode *inode, folio_put(folio); return NULL; } + bh->b_bdev = inode->i_sb->s_bdev; return bh; } -- cgit v1.2.3-73-gaa49b From 23aab037106d46e6168ce1214a958ce9bf317f2e Mon Sep 17 00:00:00 2001 From: Dmitry Antipov Date: Wed, 6 Nov 2024 12:21:00 +0300 Subject: ocfs2: fix UBSAN warning in ocfs2_verify_volume() Syzbot has reported the following splat triggered by UBSAN: UBSAN: shift-out-of-bounds in fs/ocfs2/super.c:2336:10 shift exponent 32768 is too large for 32-bit type 'int' CPU: 2 UID: 0 PID: 5255 Comm: repro Not tainted 6.12.0-rc4-syzkaller-00047-gc2ee9f594da8 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014 Call Trace: dump_stack_lvl+0x241/0x360 ? __pfx_dump_stack_lvl+0x10/0x10 ? __pfx__printk+0x10/0x10 ? __asan_memset+0x23/0x50 ? lockdep_init_map_type+0xa1/0x910 __ubsan_handle_shift_out_of_bounds+0x3c8/0x420 ocfs2_fill_super+0xf9c/0x5750 ? __pfx_ocfs2_fill_super+0x10/0x10 ? __pfx_validate_chain+0x10/0x10 ? __pfx_validate_chain+0x10/0x10 ? validate_chain+0x11e/0x5920 ? __lock_acquire+0x1384/0x2050 ? __pfx_validate_chain+0x10/0x10 ? string+0x26a/0x2b0 ? widen_string+0x3a/0x310 ? string+0x26a/0x2b0 ? bdev_name+0x2b1/0x3c0 ? pointer+0x703/0x1210 ? __pfx_pointer+0x10/0x10 ? __pfx_format_decode+0x10/0x10 ? __lock_acquire+0x1384/0x2050 ? vsnprintf+0x1ccd/0x1da0 ? snprintf+0xda/0x120 ? __pfx_lock_release+0x10/0x10 ? do_raw_spin_lock+0x14f/0x370 ? __pfx_snprintf+0x10/0x10 ? set_blocksize+0x1f9/0x360 ? sb_set_blocksize+0x98/0xf0 ? setup_bdev_super+0x4e6/0x5d0 mount_bdev+0x20c/0x2d0 ? __pfx_ocfs2_fill_super+0x10/0x10 ? __pfx_mount_bdev+0x10/0x10 ? vfs_parse_fs_string+0x190/0x230 ? __pfx_vfs_parse_fs_string+0x10/0x10 legacy_get_tree+0xf0/0x190 ? __pfx_ocfs2_mount+0x10/0x10 vfs_get_tree+0x92/0x2b0 do_new_mount+0x2be/0xb40 ? __pfx_do_new_mount+0x10/0x10 __se_sys_mount+0x2d6/0x3c0 ? __pfx___se_sys_mount+0x10/0x10 ? do_syscall_64+0x100/0x230 ? __x64_sys_mount+0x20/0xc0 do_syscall_64+0xf3/0x230 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f37cae96fda Code: 48 8b 0d 51 ce 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1e ce 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007fff6c1aa228 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fff6c1aa240 RCX: 00007f37cae96fda RDX: 00000000200002c0 RSI: 0000000020000040 RDI: 00007fff6c1aa240 RBP: 0000000000000004 R08: 00007fff6c1aa280 R09: 0000000000000000 R10: 00000000000008c0 R11: 0000000000000206 R12: 00000000000008c0 R13: 00007fff6c1aa280 R14: 0000000000000003 R15: 0000000001000000 For a really damaged superblock, the value of 'i_super.s_blocksize_bits' may exceed the maximum possible shift for an underlying 'int'. So add an extra check whether the aforementioned field represents the valid block size, which is 512 bytes, 1K, 2K, or 4K. Link: https://lkml.kernel.org/r/20241106092100.2661330-1-dmantipov@yandex.ru Fixes: ccd979bdbce9 ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem") Signed-off-by: Dmitry Antipov Reported-by: syzbot+56f7cd1abe4b8e475180@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=56f7cd1abe4b8e475180 Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Jun Piao Cc: Signed-off-by: Andrew Morton --- fs/ocfs2/super.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index 3d404624bb96..c79b4291777f 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -2319,6 +2319,7 @@ static int ocfs2_verify_volume(struct ocfs2_dinode *di, struct ocfs2_blockcheck_stats *stats) { int status = -EAGAIN; + u32 blksz_bits; if (memcmp(di->i_signature, OCFS2_SUPER_BLOCK_SIGNATURE, strlen(OCFS2_SUPER_BLOCK_SIGNATURE)) == 0) { @@ -2333,11 +2334,15 @@ static int ocfs2_verify_volume(struct ocfs2_dinode *di, goto out; } status = -EINVAL; - if ((1 << le32_to_cpu(di->id2.i_super.s_blocksize_bits)) != blksz) { + /* Acceptable block sizes are 512 bytes, 1K, 2K and 4K. */ + blksz_bits = le32_to_cpu(di->id2.i_super.s_blocksize_bits); + if (blksz_bits < 9 || blksz_bits > 12) { mlog(ML_ERROR, "found superblock with incorrect block " - "size: found %u, should be %u\n", - 1 << le32_to_cpu(di->id2.i_super.s_blocksize_bits), - blksz); + "size bits: found %u, should be 9, 10, 11, or 12\n", + blksz_bits); + } else if ((1 << le32_to_cpu(blksz_bits)) != blksz) { + mlog(ML_ERROR, "found superblock with incorrect block " + "size: found %u, should be %u\n", 1 << blksz_bits, blksz); } else if (le16_to_cpu(di->id2.i_super.s_major_rev_level) != OCFS2_MAJOR_REV_LEVEL || le16_to_cpu(di->id2.i_super.s_minor_rev_level) != -- cgit v1.2.3-73-gaa49b