| Message ID | 20250506012009.3896990-1-yi.zhang@huaweicloud.com |
|---|---|
| State | Awaiting Upstream |
| Headers | show |
| Series | [v2,1/4] ext4: fix out of bounds punch offset | expand |
On 2025/5/6 9:20, Zhang Yi wrote: > From: Zhang Yi <yi.zhang@huawei.com> > > Punching a hole with a start offset that exceeds max_end is not > permitted and will result in a negative length in the > truncate_inode_partial_folio() function while truncating the page cache, > potentially leading to undesirable consequences. > > A simple reproducer: > > truncate -s 9895604649994 /mnt/foo > xfs_io -c "pwrite 8796093022208 4096" /mnt/foo > xfs_io -c "fpunch 8796093022213 25769803777" /mnt/foo > > kernel BUG at include/linux/highmem.h:275! > Oops: invalid opcode: 0000 [#1] SMP PTI > CPU: 3 UID: 0 PID: 710 Comm: xfs_io Not tainted 6.15.0-rc3 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 > RIP: 0010:zero_user_segments.constprop.0+0xd7/0x110 > RSP: 0018:ffffc90001cf3b38 EFLAGS: 00010287 > RAX: 0000000000000005 RBX: ffffea0001485e40 RCX: 0000000000001000 > RDX: 000000000040b000 RSI: 0000000000000005 RDI: 000000000040b000 > RBP: 000000000040affb R08: ffff888000000000 R09: ffffea0000000000 > R10: 0000000000000003 R11: 00000000fffc7fc5 R12: 0000000000000005 > R13: 000000000040affb R14: ffffea0001485e40 R15: ffff888031cd3000 > FS: 00007f4f63d0b780(0000) GS:ffff8880d337d000(0000) > knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000000001ae0b038 CR3: 00000000536aa000 CR4: 00000000000006f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > truncate_inode_partial_folio+0x3dd/0x620 > truncate_inode_pages_range+0x226/0x720 > ? bdev_getblk+0x52/0x3e0 > ? ext4_get_group_desc+0x78/0x150 > ? crc32c_arch+0xfd/0x180 > ? __ext4_get_inode_loc+0x18c/0x840 > ? ext4_inode_csum+0x117/0x160 > ? jbd2_journal_dirty_metadata+0x61/0x390 > ? __ext4_handle_dirty_metadata+0xa0/0x2b0 > ? kmem_cache_free+0x90/0x5a0 > ? jbd2_journal_stop+0x1d5/0x550 > ? __ext4_journal_stop+0x49/0x100 > truncate_pagecache_range+0x50/0x80 > ext4_truncate_page_cache_block_range+0x57/0x3a0 > ext4_punch_hole+0x1fe/0x670 > ext4_fallocate+0x792/0x17d0 > ? __count_memcg_events+0x175/0x2a0 > vfs_fallocate+0x121/0x560 > ksys_fallocate+0x51/0xc0 > __x64_sys_fallocate+0x24/0x40 > x64_sys_call+0x18d2/0x4170 > do_syscall_64+0xa7/0x220 > entry_SYSCALL_64_after_hwframe+0x76/0x7e > > Fix this by filtering out cases where the punching start offset exceeds > max_end. > > Fixes: 982bf37da09d ("ext4: refactor ext4_punch_hole()") > Reported-by: Liebes Wang <wanghaichi0403@gmail.com> > Closes: https://lore.kernel.org/linux-ext4/ac3a58f6-e686-488b-a9ee-fc041024e43d@huawei.com/ > Tested-by: Liebes Wang <wanghaichi0403@gmail.com> > Signed-off-by: Zhang Yi <yi.zhang@huawei.com> > Reviewed-by: Jan Kara <jack@suse.cz> Looks good to me. Reviewed-by: Baokun Li <libaokun1@huawei.com> > --- > fs/ext4/inode.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index 94c7d2d828a6..4ec4a80b6879 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -4016,7 +4016,7 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length) > WARN_ON_ONCE(!inode_is_locked(inode)); > > /* No need to punch hole beyond i_size */ > - if (offset >= inode->i_size) > + if (offset >= inode->i_size || offset >= max_end) > return 0; > > /*
On Tue, 06 May 2025 09:20:06 +0800, Zhang Yi wrote: > Punching a hole with a start offset that exceeds max_end is not > permitted and will result in a negative length in the > truncate_inode_partial_folio() function while truncating the page cache, > potentially leading to undesirable consequences. > > A simple reproducer: > > [...] Applied, thanks! [1/4] ext4: fix out of bounds punch offset commit: b5e58bcd79625423487fa3ecba8e8411b5396327 [2/4] ext4: fix incorrect punch max_end commit: 29ec9bed2395061350249ae356fb300dd82a78e7 [3/4] ext4: factor out ext4_get_maxbytes() commit: dbe27f06fa38b9bfc598f8864ae1c5d5831d9992 [4/4] ext4: ensure i_size is smaller than maxbytes commit: 1a77a028a392fab66dd637cdfac3f888450d00af Best regards,
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 94c7d2d828a6..4ec4a80b6879 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4016,7 +4016,7 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length) WARN_ON_ONCE(!inode_is_locked(inode)); /* No need to punch hole beyond i_size */ - if (offset >= inode->i_size) + if (offset >= inode->i_size || offset >= max_end) return 0; /*