CVE-2021-47014— net/sched: act_ct: fix wild memory access when clearing fragments
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I. Basic Information for CVE-2021-47014
Vulnerability Information
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Vulnerability Title
net/sched: act_ct: fix wild memory access when clearing fragments
Source: NVD (National Vulnerability Database)
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ct: fix wild memory access when clearing fragments while testing re-assembly/re-fragmentation using act_ct, it's possible to observe a crash like the following one: KASAN: maybe wild-memory-access in range [0x0001000000000448-0x000100000000044f] CPU: 50 PID: 0 Comm: swapper/50 Tainted: G S 5.12.0-rc7+ #424 Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.4.3 01/17/2017 RIP: 0010:inet_frag_rbtree_purge+0x50/0xc0 Code: 00 fc ff df 48 89 c3 31 ed 48 89 df e8 a9 7a 38 ff 4c 89 fe 48 89 df 49 89 c6 e8 5b 3a 38 ff 48 8d 7b 40 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 75 59 48 8d bb d0 00 00 00 4c 8b 6b 40 48 89 f8 48 RSP: 0018:ffff888c31449db8 EFLAGS: 00010203 RAX: 0000200000000089 RBX: 000100000000040e RCX: ffffffff989eb960 RDX: 0000000000000140 RSI: ffffffff97cfb977 RDI: 000100000000044e RBP: 0000000000000900 R08: 0000000000000000 R09: ffffed1186289350 R10: 0000000000000003 R11: ffffed1186289350 R12: dffffc0000000000 R13: 000100000000040e R14: 0000000000000000 R15: ffff888155e02160 FS: 0000000000000000(0000) GS:ffff888c31440000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005600cb70a5b8 CR3: 0000000a2c014005 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> inet_frag_destroy+0xa9/0x150 call_timer_fn+0x2d/0x180 run_timer_softirq+0x4fe/0xe70 __do_softirq+0x197/0x5a0 irq_exit_rcu+0x1de/0x200 sysvec_apic_timer_interrupt+0x6b/0x80 </IRQ> when act_ct temporarily stores an IP fragment, restoring the skb qdisc cb results in putting random data in FRAG_CB(), and this causes those "wild" memory accesses later, when the rbtree is purged. Never overwrite the skb cb in case tcf_ct_handle_fragments() returns -EINPROGRESS.
Source: NVD (National Vulnerability Database)
CVSS Information
N/A
Source: NVD (National Vulnerability Database)
Vulnerability Type
N/A
Source: NVD (National Vulnerability Database)
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，该漏洞源于清除片段时存在内存访问问题。
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
II. Public POCs for CVE-2021-47014
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Same Patch Batch · Linux · 2024-02-28 · 86 CVEs total
| CVE-2021-46995 | can: mcp251xfd: mcp251xfd_probe(): fix an error pointer dereference in probe | |
| CVE-2021-46998 | ethernet:enic: Fix a use after free bug in enic_hard_start_xmit | |
| CVE-2021-46999 | sctp: do asoc update earlier in sctp_sf_do_dupcook_a | |
| CVE-2021-47001 | xprtrdma: Fix cwnd update ordering | |
| CVE-2021-47004 | f2fs: fix to avoid touching checkpointed data in get_victim() | |
| CVE-2021-47003 | dmaengine: idxd: Fix potential null dereference on pointer status | |
| CVE-2021-47005 | PCI: endpoint: Fix NULL pointer dereference for ->get_features() | |
| CVE-2021-47007 | f2fs: fix panic during f2fs_resize_fs() | |
| CVE-2021-47006 | ARM: 9064/1: hw_breakpoint: Do not directly check the event's overflow_handler hook | |
| CVE-2021-47002 | SUNRPC: Fix null pointer dereference in svc_rqst_free() | |
| CVE-2021-46997 | arm64: entry: always set GIC_PRIO_PSR_I_SET during entry | |
| CVE-2021-46996 | netfilter: nftables: Fix a memleak from userdata error path in new objects | |
| CVE-2021-46994 | can: mcp251x: fix resume from sleep before interface was brought up | |
| CVE-2021-46992 | netfilter: nftables: avoid overflows in nft_hash_buckets() | |
| CVE-2021-46993 | sched: Fix out-of-bound access in uclamp | |
| CVE-2021-46990 | powerpc/64s: Fix crashes when toggling entry flush barrier | |
| CVE-2021-46991 | i40e: Fix use-after-free in i40e_client_subtask() | |
| CVE-2021-46989 | hfsplus: prevent corruption in shrinking truncate | |
| CVE-2021-46987 | btrfs: fix deadlock when cloning inline extents and using qgroups | |
| CVE-2021-46988 | userfaultfd: release page in error path to avoid BUG_ON |
Showing top 20 of 86 CVEs. View all on vendor page → →
IV. Related Vulnerabilities
Same product: Linux
- CVE-2026-43500
rxrpc: Also unshare DATA/RESPONSE packets when paged frags a - CVE-2026-43475
scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT - CVE-2026-43474
fs: init flags_valid before calling vfs_fileattr_get - CVE-2026-43473
scsi: mpi3mr: Add NULL checks when resetting request and rep - CVE-2026-43472
unshare: fix unshare_fs() handling
Same vendor: Linux
- CVE-2026-43500
rxrpc: Also unshare DATA/RESPONSE packets when paged frags a - CVE-2026-43475
scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT - CVE-2026-43474
fs: init flags_valid before calling vfs_fileattr_get - CVE-2026-43473
scsi: mpi3mr: Add NULL checks when resetting request and rep - CVE-2026-43472
unshare: fix unshare_fs() handling
V. Comments for CVE-2021-47014
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