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CVE-2022-49347— ext4: fix bug_on in ext4_writepages

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于ext4_writepages未正确处理块位图不一致，可能导致内核崩溃。

AI Predicted 7.8 Difficulty: Moderate EPSS 0.29% · P22

Possible ATT&CK Techniques 1 AI

T1499 · Endpoint Denial of Service

Affected Version Matrix 20

VendorProduct Version RangeStatus
Linux Linux 3c47d54170b6a678875566b1b8d6dcf57904e49b< 19918ec7717d87d5ab825884a46b26b21375d7ce affected
3c47d54170b6a678875566b1b8d6dcf57904e49b< b2b78f5bf2d453dda3903955efee059260787a42 affected
3c47d54170b6a678875566b1b8d6dcf57904e49b< de1732b5c1693ad489c5d254f124f67cb775f37d affected
3c47d54170b6a678875566b1b8d6dcf57904e49b< 73fd5b19285197078ee8a2e651d75d5b094a4de9 affected
3c47d54170b6a678875566b1b8d6dcf57904e49b< 1b061af037646c9cdb0afd8a8d2f1e1c06285866 affected
3c47d54170b6a678875566b1b8d6dcf57904e49b< 18a759f7f99f0b65a08ff5b7e745fc405a42bde4 affected
3c47d54170b6a678875566b1b8d6dcf57904e49b< 1cde35417edc0370fb0179a4e38b78a15350a8d0 affected
3c47d54170b6a678875566b1b8d6dcf57904e49b< 013f12bdedb96816aaa27ee04349f4433d361f52 affected
… +12 more rows
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I. Basic Information for CVE-2022-49347

Vulnerability Information
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Vulnerability Title
ext4: fix bug_on in ext4_writepages
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: ext4: fix bug_on in ext4_writepages we got issue as follows: EXT4-fs error (device loop0): ext4_mb_generate_buddy:1141: group 0, block bitmap and bg descriptor inconsistent: 25 vs 31513 free cls ------------[ cut here ]------------ kernel BUG at fs/ext4/inode.c:2708! invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 2 PID: 2147 Comm: rep Not tainted 5.18.0-rc2-next-20220413+ #155 RIP: 0010:ext4_writepages+0x1977/0x1c10 RSP: 0018:ffff88811d3e7880 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff88811c098000 RDX: 0000000000000000 RSI: ffff88811c098000 RDI: 0000000000000002 RBP: ffff888128140f50 R08: ffffffffb1ff6387 R09: 0000000000000000 R10: 0000000000000007 R11: ffffed10250281ea R12: 0000000000000001 R13: 00000000000000a4 R14: ffff88811d3e7bb8 R15: ffff888128141028 FS: 00007f443aed9740(0000) GS:ffff8883aef00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020007200 CR3: 000000011c2a4000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> do_writepages+0x130/0x3a0 filemap_fdatawrite_wbc+0x83/0xa0 filemap_flush+0xab/0xe0 ext4_alloc_da_blocks+0x51/0x120 __ext4_ioctl+0x1534/0x3210 __x64_sys_ioctl+0x12c/0x170 do_syscall_64+0x3b/0x90 It may happen as follows: 1. write inline_data inode vfs_write new_sync_write ext4_file_write_iter ext4_buffered_write_iter generic_perform_write ext4_da_write_begin ext4_da_write_inline_data_begin -> If inline data size too small will allocate block to write, then mapping will has dirty page ext4_da_convert_inline_data_to_extent ->clear EXT4_STATE_MAY_INLINE_DATA 2. fallocate do_vfs_ioctl ioctl_preallocate vfs_fallocate ext4_fallocate ext4_convert_inline_data ext4_convert_inline_data_nolock ext4_map_blocks -> fail will goto restore data ext4_restore_inline_data ext4_create_inline_data ext4_write_inline_data ext4_set_inode_state -> set inode EXT4_STATE_MAY_INLINE_DATA 3. writepages __ext4_ioctl ext4_alloc_da_blocks filemap_flush filemap_fdatawrite_wbc do_writepages ext4_writepages if (ext4_has_inline_data(inode)) BUG_ON(ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) The root cause of this issue is we destory inline data until call ext4_writepages under delay allocation mode. But there maybe already convert from inline to extent. To solve this issue, we call filemap_flush first..
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于ext4_writepages未正确处理块位图不一致，可能导致内核崩溃。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux 3c47d54170b6a678875566b1b8d6dcf57904e49b ~ 19918ec7717d87d5ab825884a46b26b21375d7ce -
Linux Linux 3.8 -

II. Public POCs for CVE-2022-49347

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III. Intelligence Information for CVE-2022-49347

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Patches & Fixes for CVE-2022-49347 (9)

Same Patch Batch · Linux · 2025-02-26 · 706 CVEs total

CVE-2022-49149 9.8 CRITICAL rxrpc: Fix call timer start racing with call destruction
CVE-2022-49561 9.8 CRITICAL netfilter: conntrack: re-fetch conntrack after insertion
CVE-2022-49407 9.8 CRITICAL dlm: fix plock invalid read
CVE-2022-49362 9.8 CRITICAL NFSD: Fix potential use-after-free in nfsd_file_put()
CVE-2022-49280 9.8 CRITICAL NFSD: prevent underflow in nfssvc_decode_writeargs()
CVE-2022-49356 9.8 CRITICAL SUNRPC: Trap RDMA segment overflows
CVE-2022-49418 9.8 CRITICAL NFSv4: Fix free of uninitialized nfs4_label on referral lookup.
CVE-2022-49094 9.8 CRITICAL net/tls: fix slab-out-of-bounds bug in decrypt_internal
CVE-2022-49093 9.8 CRITICAL skbuff: fix coalescing for page_pool fragment recycling
CVE-2022-49260 9.8 CRITICAL crypto: hisilicon/sec - fix the aead software fallback for engine
CVE-2022-49194 9.8 CRITICAL net: bcmgenet: Use stronger register read/writes to assure ordering
CVE-2022-49201 9.8 CRITICAL ibmvnic: fix race between xmit and reset
CVE-2022-49058 9.1 CRITICAL cifs: potential buffer overflow in handling symlinks
CVE-2022-49535 8.8 HIGH scsi: lpfc: Fix null pointer dereference after failing to issue FLOGI and PLOGI
CVE-2022-49159 8.8 HIGH scsi: qla2xxx: Implement ref count for SRB
CVE-2022-49138 8.8 HIGH Bluetooth: hci_event: Ignore multiple conn complete events
CVE-2022-49479 8.8 HIGH mt76: fix tx status related use-after-free race on station removal
CVE-2022-49470 8.8 HIGH Bluetooth: btmtksdio: fix use-after-free at btmtksdio_recv_event
CVE-2022-49111 8.8 HIGH Bluetooth: Fix use after free in hci_send_acl
CVE-2022-49114 8.8 HIGH scsi: libfc: Fix use after free in fc_exch_abts_resp()

Showing top 20 of 706 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2022-49347

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