From: Sagi Grimberg Date: Mon, 24 Aug 2015 16:04:51 +0000 (+0300) Subject: IB/srp: Fix possible protection fault X-Git-Tag: omap-for-v4.3/fixes-rc1~52^2~2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7fbc67df2cd6d0b72fd5d6d3acaa79ab6f5b0224;p=pandora-kernel.git IB/srp: Fix possible protection fault srp_destroy_qp is designed to indicate we are safe to continue with freeing the channel resources by modifying the qp error state, posting a dummy wr on the queue-pair and waiting for it to flush. This also holds for the channel registration pool as we are unmapping the memory region when handling a scsi response. Destroying the channel registration pool before we make sure we processed all the inflight IO might introduce a use-after-free of the registration pool. This use-after-free is demonstrated in the stack trace below where srp is trying to unmap a used FMR after the fmr_pool was already destroyed. general protection fault: 0000 [#1] SMP RIP: 0010:[] [] _raw_spin_lock_irqsave+0x1b/0x50 Call Trace: [] ib_fmr_pool_unmap+0x1a/0xb0 [ib_core] [] srp_unmap_data.isra.28+0x17d/0x250 [ib_srp] [] srp_free_req+0x2b/0x60 [ib_srp] [] srp_recv_completion+0x174/0x580 [ib_srp] [] mlx4_eq_int+0x4de/0xe50 [mlx4_core] [] mlx4_msi_x_interrupt+0x10/0x20 [mlx4_core] [] handle_irq_event_percpu+0x35/0x1b0 [] handle_irq_event+0x32/0x50 [] handle_edge_irq+0x6f/0x120 [] handle_irq+0x1a/0x30 [] do_IRQ+0x45/0xb0 [] common_interrupt+0x6d/0x6d [] cpuidle_enter_state+0x4f/0xc0 [] cpuidle_idle_call+0xcc/0x210 [] arch_cpu_idle+0xa/0x30 [] cpu_startup_entry+0xe1/0x270 [] start_secondary+0x21a/0x2c0 Reported-by: Eliott Kespi Signed-off-by: Sagi Grimberg Signed-off-by: Bart Van Assche Signed-off-by: Doug Ledford --- Reading git-diff-tree failed