| From 145788c6387a941ff9326af2b324d7a905798e6f Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Wed, 30 Mar 2022 09:49:28 -0700 |
| Subject: fs: fix an infinite loop in iomap_fiemap |
| |
| From: Guo Xuenan <guoxuenan@huawei.com> |
| |
| [ Upstream commit 49df34221804cfd6384135b28b03c9461a31d024 ] |
| |
| when get fiemap starting from MAX_LFS_FILESIZE, (maxbytes - *len) < start |
| will always true , then *len set zero. because of start offset is beyond |
| file size, for erofs filesystem it will always return iomap.length with |
| zero,iomap iterate will enter infinite loop. it is necessary cover this |
| corner case to avoid this situation. |
| |
| ------------[ cut here ]------------ |
| WARNING: CPU: 7 PID: 905 at fs/iomap/iter.c:35 iomap_iter+0x97f/0xc70 |
| Modules linked in: xfs erofs |
| CPU: 7 PID: 905 Comm: iomap Tainted: G W 5.17.0-rc8 #27 |
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 |
| RIP: 0010:iomap_iter+0x97f/0xc70 |
| Code: 85 a1 fc ff ff e8 71 be 9c ff 0f 1f 44 00 00 e9 92 fc ff ff e8 62 be 9c ff 0f 0b b8 fb ff ff ff e9 fc f8 ff ff e8 51 be 9c ff <0f> 0b e9 2b fc ff ff e8 45 be 9c ff 0f 0b e9 e1 fb ff ff e8 39 be |
| RSP: 0018:ffff888060a37ab0 EFLAGS: 00010293 |
| RAX: 0000000000000000 RBX: ffff888060a37bb0 RCX: 0000000000000000 |
| RDX: ffff88807e19a900 RSI: ffffffff81a7da7f RDI: ffff888060a37be0 |
| RBP: 7fffffffffffffff R08: 0000000000000000 R09: ffff888060a37c20 |
| R10: ffff888060a37c67 R11: ffffed100c146f8c R12: 7fffffffffffffff |
| R13: 0000000000000000 R14: ffff888060a37bd8 R15: ffff888060a37c20 |
| FS: 00007fd3cca01540(0000) GS:ffff888108780000(0000) knlGS:0000000000000000 |
| CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| CR2: 0000000020010820 CR3: 0000000054b92000 CR4: 00000000000006e0 |
| DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 |
| DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 |
| Call Trace: |
| <TASK> |
| iomap_fiemap+0x1c9/0x2f0 |
| erofs_fiemap+0x64/0x90 [erofs] |
| do_vfs_ioctl+0x40d/0x12e0 |
| __x64_sys_ioctl+0xaa/0x1c0 |
| do_syscall_64+0x35/0x80 |
| entry_SYSCALL_64_after_hwframe+0x44/0xae |
| </TASK> |
| ---[ end trace 0000000000000000 ]--- |
| watchdog: BUG: soft lockup - CPU#7 stuck for 26s! [iomap:905] |
| |
| Reported-by: Hulk Robot <hulkci@huawei.com> |
| Signed-off-by: Guo Xuenan <guoxuenan@huawei.com> |
| Reviewed-by: Christoph Hellwig <hch@lst.de> |
| [djwong: fix some typos] |
| Reviewed-by: Darrick J. Wong <djwong@kernel.org> |
| Signed-off-by: Darrick J. Wong <djwong@kernel.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| fs/ioctl.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| diff --git a/fs/ioctl.c b/fs/ioctl.c |
| index 1ed097e94af2..85f7e4ee6924 100644 |
| --- a/fs/ioctl.c |
| +++ b/fs/ioctl.c |
| @@ -173,7 +173,7 @@ int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo, |
| |
| if (*len == 0) |
| return -EINVAL; |
| - if (start > maxbytes) |
| + if (start >= maxbytes) |
| return -EFBIG; |
| |
| /* |
| -- |
| 2.35.1 |
| |