CVE-2025-21851

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix softlockup in arena_map_free on 64k page kernel On an aarch64 kernel with CONFIG_PAGE_SIZE_64KB=y, arena_htab tests cause a segmentation fault and soft lockup. The same failure is not observed with 4k pages on aarch64. It turns out arena_map_free() is calling apply_to_existing_page_range() with the address returned by bpf_arena_get_kern_vm_start(). If this address is not page-aligned the code ends up calling apply_to_pte_range() with that unaligned address causing soft lockup. Fix it by round up GUARD_SZ to PAGE_SIZE << 1 so that the division by 2 in bpf_arena_get_kern_vm_start() returns a page-aligned value.

Reserved 2024-12-29 | Published 2025-03-12 | Updated 2025-03-12 | Assigner Linux

Product status

Default status
unaffected

317460317a02a1af512697e6e964298dedd8a163 before c1f3f3892d4526f18aaeffdb6068ce861e793ee3
affected

317460317a02a1af512697e6e964298dedd8a163 before 787d556a3de447e70964a4bdeba9196f62a62b1e
affected

317460317a02a1af512697e6e964298dedd8a163 before 517e8a7835e8cfb398a0aeb0133de50e31cae32b
affected

Default status
affected

6.9
affected

Any version before 6.9
unaffected

6.12.17
unaffected

6.13.5
unaffected

6.14-rc4
unaffected

References

git.kernel.org/...c/c1f3f3892d4526f18aaeffdb6068ce861e793ee3

git.kernel.org/...c/787d556a3de447e70964a4bdeba9196f62a62b1e

git.kernel.org/...c/517e8a7835e8cfb398a0aeb0133de50e31cae32b

cve.org (CVE-2025-21851)

nvd.nist.gov (CVE-2025-21851)

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