Add reference counting to all the objects #4
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planetA
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Jakub Sitnicki says: ==================== This patch set addresses the syzbot report in [1]. Patch #1 has been suggested by Eric [2]. I extended it to cover the rest of sock_map proto callbacks. Otherwise we would still overflow the stack. Patch #2 contains the actual fix and bug analysis. Patches #3 & #4 add coverage to selftests to trigger the bug. [1] https://lore.kernel.org/all/[email protected]/ [2] https://lore.kernel.org/all/CANn89iK2UN1FmdUcH12fv_xiZkv2G+Nskvmq7fG6aA_6VKRf6g@mail.gmail.com/ --- v1 -> v2: v1: https://lore.kernel.org/r/[email protected] [v1 didn't hit bpf@ ML by mistake] * pull in Eric's patch to protect against recursion loop bugs (Eric) * add a macro helper to check if pointer is inside a memory range (Eric) ==================== Signed-off-by: Alexei Starovoitov <[email protected]>
planetA
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During EEH error injection testing, a deadlock was encountered in the tg3 driver when tg3_io_error_detected() was attempting to cancel outstanding reset tasks: crash> foreach UN bt ... PID: 159 TASK: c0000000067c6000 CPU: 8 COMMAND: "eehd" ... #5 [c00000000681f990] __cancel_work_timer at c00000000019fd18 #6 [c00000000681fa30] tg3_io_error_detected at c00800000295f098 [tg3] #7 [c00000000681faf0] eeh_report_error at c00000000004e25c ... PID: 290 TASK: c000000036e5f800 CPU: 6 COMMAND: "kworker/6:1" ... #4 [c00000003721fbc0] rtnl_lock at c000000000c940d8 #5 [c00000003721fbe0] tg3_reset_task at c008000002969358 [tg3] #6 [c00000003721fc60] process_one_work at c00000000019e5c4 ... PID: 296 TASK: c000000037a65800 CPU: 21 COMMAND: "kworker/21:1" ... #4 [c000000037247bc0] rtnl_lock at c000000000c940d8 #5 [c000000037247be0] tg3_reset_task at c008000002969358 [tg3] #6 [c000000037247c60] process_one_work at c00000000019e5c4 ... PID: 655 TASK: c000000036f49000 CPU: 16 COMMAND: "kworker/16:2" ...:1 #4 [c0000000373ebbc0] rtnl_lock at c000000000c940d8 #5 [c0000000373ebbe0] tg3_reset_task at c008000002969358 [tg3] #6 [c0000000373ebc60] process_one_work at c00000000019e5c4 ... Code inspection shows that both tg3_io_error_detected() and tg3_reset_task() attempt to acquire the RTNL lock at the beginning of their code blocks. If tg3_reset_task() should happen to execute between the times when tg3_io_error_deteced() acquires the RTNL lock and tg3_reset_task_cancel() is called, a deadlock will occur. Moving tg3_reset_task_cancel() call earlier within the code block, prior to acquiring RTNL, prevents this from happening, but also exposes another deadlock issue where tg3_reset_task() may execute AFTER tg3_io_error_detected() has executed: crash> foreach UN bt PID: 159 TASK: c0000000067d2000 CPU: 9 COMMAND: "eehd" ... #4 [c000000006867a60] rtnl_lock at c000000000c940d8 #5 [c000000006867a80] tg3_io_slot_reset at c0080000026c2ea8 [tg3] #6 [c000000006867b00] eeh_report_reset at c00000000004de88 ... PID: 363 TASK: c000000037564000 CPU: 6 COMMAND: "kworker/6:1" ... #3 [c000000036c1bb70] msleep at c000000000259e6c #4 [c000000036c1bba0] napi_disable at c000000000c6b848 #5 [c000000036c1bbe0] tg3_reset_task at c0080000026d942c [tg3] #6 [c000000036c1bc60] process_one_work at c00000000019e5c4 ... This issue can be avoided by aborting tg3_reset_task() if EEH error recovery is already in progress. Fixes: db84bf4 ("tg3: tg3_reset_task() needs to use rtnl_lock to synchronize") Signed-off-by: David Christensen <[email protected]> Reviewed-by: Pavan Chebbi <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
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All these kfrees inside
ovey_verbs.cmust beref_downThe text was updated successfully, but these errors were encountered: