• Sukadev Bhattiprolu's avatar
    ibmvnic: don't release napi in __ibmvnic_open() · 61772b09
    Sukadev Bhattiprolu authored
    If __ibmvnic_open() encounters an error such as when setting link state,
    it calls release_resources() which frees the napi structures needlessly.
    Instead, have __ibmvnic_open() only clean up the work it did so far (i.e.
    disable napi and irqs) and leave the rest to the callers.
    
    If caller of __ibmvnic_open() is ibmvnic_open(), it should release the
    resources immediately. If the caller is do_reset() or do_hard_reset(),
    they will release the resources on the next reset.
    
    This fixes following crash that occurred when running the drmgr command
    several times to add/remove a vnic interface:
    
    	[102056] ibmvnic 30000003 env3: Disabling rx_scrq[6] irq
    	[102056] ibmvnic 30000003 env3: Disabling rx_scrq[7] irq
    	[102056] ibmvnic 30000003 env3: Replenished 8 pools
    	Kernel attempted to read user page (10) - exploit attempt? (uid: 0)
    	BUG: Kernel NULL pointer dereference on read at 0x00000010
    	Faulting instruction address: 0xc000000000a3c840
    	Oops: Kernel access of bad area, sig: 11 [#1]
    	LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
    	...
    	CPU: 9 PID: 102056 Comm: kworker/9:2 Kdump: loaded Not tainted 5.16.0-rc5-autotest-g6441998e #1
    	Workqueue: events_long __ibmvnic_reset [ibmvnic]
    	NIP:  c000000000a3c840 LR: c0080000029b5378 CTR: c000000000a3c820
    	REGS: c0000000548e37e0 TRAP: 0300   Not tainted  (5.16.0-rc5-autotest-g6441998e)
    	MSR:  8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 28248484  XER: 00000004
    	CFAR: c0080000029bdd24 DAR: 0000000000000010 DSISR: 40000000 IRQMASK: 0
    	GPR00: c0080000029b55d0 c0000000548e3a80 c0000000028f0200 0000000000000000
    	...
    	NIP [c000000000a3c840] napi_enable+0x20/0xc0
    	LR [c0080000029b5378] __ibmvnic_open+0xf0/0x430 [ibmvnic]
    	Call Trace:
    	[c0000000548e3a80] [0000000000000006] 0x6 (unreliable)
    	[c0000000548e3ab0] [c0080000029b55d0] __ibmvnic_open+0x348/0x430 [ibmvnic]
    	[c0000000548e3b40] [c0080000029bcc28] __ibmvnic_reset+0x500/0xdf0 [ibmvnic]
    	[c0000000548e3c60] [c000000000176228] process_one_work+0x288/0x570
    	[c0000000548e3d00] [c000000000176588] worker_thread+0x78/0x660
    	[c0000000548e3da0] [c0000000001822f0] kthread+0x1c0/0x1d0
    	[c0000000548e3e10] [c00000000000cf64] ret_from_kernel_thread+0x5c/0x64
    	Instruction dump:
    	7d2948f8 792307e0 4e800020 60000000 3c4c01eb 384239e0 f821ffd1 39430010
    	38a0fff6 e92d1100 f9210028 39200000 <e9030010> f9010020 60420000 e9210020
    	---[ end trace 5f8033b08fd27706 ]---
    
    Fixes: ed651a10 ("ibmvnic: Updated reset handling")
    Reported-by: default avatarAbdul Haleem <abdhalee@linux.vnet.ibm.com>
    Signed-off-by: default avatarSukadev Bhattiprolu <sukadev@linux.ibm.com>
    Reviewed-by: default avatarDany Madden <drt@linux.ibm.com>
    Link: https://lore.kernel.org/r/20220208001918.900602-1-sukadev@linux.ibm.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
    61772b09
ibmvnic.c 164 KB