{"id":"AZL-74676","summary":"CVE-2025-39782 affecting package kernel for versions less than 5.15.200.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\njbd2: prevent softlockup in jbd2_log_do_checkpoint()\n\nBoth jbd2_log_do_checkpoint() and jbd2_journal_shrink_checkpoint_list()\nperiodically release j_list_lock after processing a batch of buffers to\navoid long hold times on the j_list_lock. However, since both functions\ncontend for j_list_lock, the combined time spent waiting and processing\ncan be significant.\n\njbd2_journal_shrink_checkpoint_list() explicitly calls cond_resched() when\nneed_resched() is true to avoid softlockups during prolonged operations.\nBut jbd2_log_do_checkpoint() only exits its loop when need_resched() is\ntrue, relying on potentially sleeping functions like __flush_batch() or\nwait_on_buffer() to trigger rescheduling. If those functions do not sleep,\nthe kernel may hit a softlockup.\n\nwatchdog: BUG: soft lockup - CPU#3 stuck for 156s! [kworker/u129:2:373]\nCPU: 3 PID: 373 Comm: kworker/u129:2 Kdump: loaded Not tainted 6.6.0+ #10\nHardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.27 06/13/2017\nWorkqueue: writeback wb_workfn (flush-7:2)\npstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)\npc : native_queued_spin_lock_slowpath+0x358/0x418\nlr : jbd2_log_do_checkpoint+0x31c/0x438 [jbd2]\nCall trace:\n native_queued_spin_lock_slowpath+0x358/0x418\n jbd2_log_do_checkpoint+0x31c/0x438 [jbd2]\n __jbd2_log_wait_for_space+0xfc/0x2f8 [jbd2]\n add_transaction_credits+0x3bc/0x418 [jbd2]\n start_this_handle+0xf8/0x560 [jbd2]\n jbd2__journal_start+0x118/0x228 [jbd2]\n __ext4_journal_start_sb+0x110/0x188 [ext4]\n ext4_do_writepages+0x3dc/0x740 [ext4]\n ext4_writepages+0xa4/0x190 [ext4]\n do_writepages+0x94/0x228\n __writeback_single_inode+0x48/0x318\n writeback_sb_inodes+0x204/0x590\n __writeback_inodes_wb+0x54/0xf8\n wb_writeback+0x2cc/0x3d8\n wb_do_writeback+0x2e0/0x2f8\n wb_workfn+0x80/0x2a8\n process_one_work+0x178/0x3e8\n worker_thread+0x234/0x3b8\n kthread+0xf0/0x108\n ret_from_fork+0x10/0x20\n\nSo explicitly call cond_resched() in jbd2_log_do_checkpoint() to avoid\nsoftlockup.","modified":"2026-04-01T05:22:45.539267Z","published":"2025-09-11T17:15:44Z","upstream":["CVE-2025-39782"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-39782"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.200.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-74676.json"}}],"schema_version":"1.7.5"}