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CVE-2021-47462— mm/mempolicy: do not allow illegal MPOL_F_NUMA_BALANCING | MPOL_LOCAL in mbind()

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，该漏洞源于未初始化内存。

AI Predicted 5.5 Difficulty: Moderate EPSS 0.18% · P7

Affected Version Matrix 6

VendorProduct Version RangeStatus
Linux Linux bda420b985054a3badafef23807c4b4fa38a3dff< 9ee4e9ae98f1f262d6fae0d266cfdf3ba2c321d9 affected
bda420b985054a3badafef23807c4b4fa38a3dff< 6d2aec9e123bb9c49cb5c7fc654f25f81e688e8c affected
5.12 affected
< 5.12 unaffected
5.14.15≤ 5.14.* unaffected
5.15≤ * unaffected
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I. Basic Information for CVE-2021-47462

Vulnerability Information
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Vulnerability Title
mm/mempolicy: do not allow illegal MPOL_F_NUMA_BALANCING | MPOL_LOCAL in mbind()
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: mm/mempolicy: do not allow illegal MPOL_F_NUMA_BALANCING | MPOL_LOCAL in mbind() syzbot reported access to unitialized memory in mbind() [1] Issue came with commit bda420b98505 ("numa balancing: migrate on fault among multiple bound nodes") This commit added a new bit in MPOL_MODE_FLAGS, but only checked valid combination (MPOL_F_NUMA_BALANCING can only be used with MPOL_BIND) in do_set_mempolicy() This patch moves the check in sanitize_mpol_flags() so that it is also used by mbind() [1] BUG: KMSAN: uninit-value in __mpol_equal+0x567/0x590 mm/mempolicy.c:2260 __mpol_equal+0x567/0x590 mm/mempolicy.c:2260 mpol_equal include/linux/mempolicy.h:105 [inline] vma_merge+0x4a1/0x1e60 mm/mmap.c:1190 mbind_range+0xcc8/0x1e80 mm/mempolicy.c:811 do_mbind+0xf42/0x15f0 mm/mempolicy.c:1333 kernel_mbind mm/mempolicy.c:1483 [inline] __do_sys_mbind mm/mempolicy.c:1490 [inline] __se_sys_mbind+0x437/0xb80 mm/mempolicy.c:1486 __x64_sys_mbind+0x19d/0x200 mm/mempolicy.c:1486 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was created at: slab_alloc_node mm/slub.c:3221 [inline] slab_alloc mm/slub.c:3230 [inline] kmem_cache_alloc+0x751/0xff0 mm/slub.c:3235 mpol_new mm/mempolicy.c:293 [inline] do_mbind+0x912/0x15f0 mm/mempolicy.c:1289 kernel_mbind mm/mempolicy.c:1483 [inline] __do_sys_mbind mm/mempolicy.c:1490 [inline] __se_sys_mbind+0x437/0xb80 mm/mempolicy.c:1486 __x64_sys_mbind+0x19d/0x200 mm/mempolicy.c:1486 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae ===================================================== Kernel panic - not syncing: panic_on_kmsan set ... CPU: 0 PID: 15049 Comm: syz-executor.0 Tainted: G B 5.15.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1ff/0x28e lib/dump_stack.c:106 dump_stack+0x25/0x28 lib/dump_stack.c:113 panic+0x44f/0xdeb kernel/panic.c:232 kmsan_report+0x2ee/0x300 mm/kmsan/report.c:186 __msan_warning+0xd7/0x150 mm/kmsan/instrumentation.c:208 __mpol_equal+0x567/0x590 mm/mempolicy.c:2260 mpol_equal include/linux/mempolicy.h:105 [inline] vma_merge+0x4a1/0x1e60 mm/mmap.c:1190 mbind_range+0xcc8/0x1e80 mm/mempolicy.c:811 do_mbind+0xf42/0x15f0 mm/mempolicy.c:1333 kernel_mbind mm/mempolicy.c:1483 [inline] __do_sys_mbind mm/mempolicy.c:1490 [inline] __se_sys_mbind+0x437/0xb80 mm/mempolicy.c:1486 __x64_sys_mbind+0x19d/0x200 mm/mempolicy.c:1486 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae
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，该漏洞源于未初始化内存。
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 bda420b985054a3badafef23807c4b4fa38a3dff ~ 9ee4e9ae98f1f262d6fae0d266cfdf3ba2c321d9 -
Linux Linux 5.12 -

II. Public POCs for CVE-2021-47462

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III. Intelligence Information for CVE-2021-47462

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Other References for CVE-2021-47462 (2)

Same Patch Batch · Linux · 2024-05-22 · 63 CVEs total

CVE-2021-47496 9.8 CRITICAL net/tls: Fix flipped sign in tls_err_abort() calls
CVE-2021-47478 9.1 CRITICAL isofs: Fix out of bound access for corrupted isofs image
CVE-2021-47450 8.8 HIGH KVM: arm64: Fix host stage-2 PGD refcount
CVE-2021-47433 8.1 HIGH btrfs: fix abort logic in btrfs_replace_file_extents
CVE-2021-47446 7.8 HIGH drm/msm/a4xx: fix error handling in a4xx_gpu_init()
CVE-2021-47493 7.8 HIGH ocfs2: fix race between searching chunks and release journal_head from buffer_head
CVE-2021-47492 7.8 HIGH mm, thp: bail out early in collapse_file for writeback page
CVE-2021-47494 7.8 HIGH cfg80211: fix management registrations locking
CVE-2021-47451 7.8 HIGH netfilter: xt_IDLETIMER: fix panic that occurs when timer_type has garbage value
CVE-2021-47447 7.8 HIGH drm/msm/a3xx: fix error handling in a3xx_gpu_init()
CVE-2021-47485 7.8 HIGH IB/qib: Protect from buffer overflow in struct qib_user_sdma_pkt fields
CVE-2021-47483 7.8 HIGH regmap: Fix possible double-free in regcache_rbtree_exit()
CVE-2021-47459 7.8 HIGH can: j1939: j1939_netdev_start(): fix UAF for rx_kref of j1939_priv
CVE-2021-47461 7.8 HIGH userfaultfd: fix a race between writeprotect and exit_mmap()
CVE-2021-47448 7.5 HIGH mptcp: fix possible stall on recvmsg()
CVE-2021-47438 7.1 HIGH net/mlx5e: Fix memory leak in mlx5_core_destroy_cq() error path
CVE-2021-47465 7.1 HIGH KVM: PPC: Book3S HV: Fix stack handling in idle_kvm_start_guest()
CVE-2021-47458 7.1 HIGH ocfs2: mount fails with buffer overflow in strlen
CVE-2021-47497 nvmem: Fix shift-out-of-bound (UBSAN) with byte size cells
CVE-2021-47498 dm rq: don't queue request to blk-mq during DM suspend

Showing top 20 of 63 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2021-47462

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