In the Linux kernel, the following vulnerability has been resolved:
mm/memory-failure: make sure wait for page writeback in memory_failure
Our syzkaller trigger the "BUG_ON(!list_empty(&inode->i_wb_list))" in clear_inode:
kernel BUG at fs/inode.c:519! Internal error: Oops - BUG: 0 [#1] SMP Modules linked in: Process syz-executor.0 (pid: 249, stack limit = 0x00000000a12409d7) CPU: 1 PID: 249 Comm: syz-executor.0 Not tainted 4.19.95 Hardware name: linux,dummy-virt (DT) pstate: 80000005 (Nzcv daif -PAN -UAO) pc : clear_inode+0x280/0x2a8 lr : clear_inode+0x280/0x2a8 Call trace: clear_inode+0x280/0x2a8 ext4_clear_inode+0x38/0xe8 ext4_free_inode+0x130/0xc68 ext4_evict_inode+0xb20/0xcb8 evict+0x1a8/0x3c0 iput+0x344/0x460 do_unlinkat+0x260/0x410 __arm64_sys_unlinkat+0x6c/0xc0 el0_svc_common+0xdc/0x3b0 el0_svc_handler+0xf8/0x160 el0_svc+0x10/0x218 Kernel panic - not syncing: Fatal exception
A crash dump of this problem show that someone called __munlock_pagevec to clear page LRU without lock_page: do_mmap -> mmap_region -> do_munmap -> munlock_vma_pages_range -> __munlock_pagevec.
As a result memory_failure will call identify_page_state without wait_on_page_writeback. And after truncate_error_page clear the mapping of this page. end_page_writeback won't call sb_clear_inode_writeback to clear inode->i_wb_list. That will trigger BUG_ON in clear_inode!
Fix it by checking PageWriteback too to help determine should we skip wait_on_page_writeback.
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon Linux Ami 2 | — | Upgrade kernel-toolsUpgrade kernel-tools-develUpgrade perf-debuginfoUpgrade kernelUpgrade kernel-livepatch-4.14.238-182.421Upgrade perfUpgrade python-perf-debuginfoUpgrade bpftool-debuginfoUpgrade bpftoolUpgrade kernel-tools-debuginfoUpgrade kernel-headersUpgrade kernel-debuginfoUpgrade kernel-develUpgrade python-perfUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-debuginfo-common-aarch64 | Dec 12, 2024 | May 21, 2024 |
| Debian | — | Upgrade linux | Jul 30, 2024 | May 21, 2024 |
| Redhat_linux | — | No solution exists | Jul 9, 2025 | May 21, 2024 |
| Ubuntu | — | Upgrade linux-azure-fipsUpgrade linux-gcp-4.15Upgrade linux-hweUpgrade linux-gcp-fipsUpgrade linux-aws-fipsUpgrade linux-azure-5.4Upgrade linuxUpgrade linux-gcp-5.4Upgrade linux-gkeopUpgrade linux-oracleUpgrade linux-azure-4.15Upgrade linux-aws-hweUpgrade linux-hwe-5.4Upgrade linux-fipsUpgrade linux-kvmUpgrade linux-aws-5.4Upgrade linux-gcpUpgrade linux-raspiUpgrade linux-awsUpgrade linux-raspi-5.4Upgrade linux-bluefieldUpgrade linux-oracle-5.4Upgrade linux-azure | Nov 19, 2024 | May 21, 2024 |
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