From 77f8269606bf95fcb232ee86f6da80886f1dfae8 Mon Sep 17 00:00:00 2001 From: Yang Yingliang Date: Wed, 16 Jan 2019 13:33:22 +0800 Subject: [PATCH] ipmi: fix use-after-free of user->release_barrier.rda When we do the following test, we got oops in ipmi_msghandler driver while((1)) do service ipmievd restart & service ipmievd restart done --------------------------------------------------------------- [ 294.230186] Unable to handle kernel paging request at virtual address 0000803fea6ea008 [ 294.230188] Mem abort info: [ 294.230190] ESR = 0x96000004 [ 294.230191] Exception class = DABT (current EL), IL = 32 bits [ 294.230193] SET = 0, FnV = 0 [ 294.230194] EA = 0, S1PTW = 0 [ 294.230195] Data abort info: [ 294.230196] ISV = 0, ISS = 0x00000004 [ 294.230197] CM = 0, WnR = 0 [ 294.230199] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000a1c1b75a [ 294.230201] [0000803fea6ea008] pgd=0000000000000000 [ 294.230204] Internal error: Oops: 96000004 [#1] SMP [ 294.235211] Modules linked in: nls_utf8 isofs rpcrdma ib_iser ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib rdma_ucm ib_umad rdma_cm ib_cm iw_cm dm_mirror dm_region_hash dm_log dm_mod aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce sha2_ce ses sha256_arm64 sha1_ce hibmc_drm hisi_sas_v2_hw enclosure sg hisi_sas_main sbsa_gwdt ip_tables mlx5_ib ib_uverbs marvell ib_core mlx5_core ixgbe ipmi_si mdio hns_dsaf ipmi_devintf ipmi_msghandler hns_enet_drv hns_mdio [ 294.277745] CPU: 3 PID: 0 Comm: swapper/3 Kdump: loaded Not tainted 5.0.0-rc2+ #113 [ 294.285511] Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.37 11/21/2017 [ 294.292835] pstate: 80000005 (Nzcv daif -PAN -UAO) [ 294.297695] pc : __srcu_read_lock+0x38/0x58 [ 294.301940] lr : acquire_ipmi_user+0x2c/0x70 [ipmi_msghandler] [ 294.307853] sp : ffff00001001bc80 [ 294.311208] x29: ffff00001001bc80 x28: ffff0000117e5000 [ 294.316594] x27: 0000000000000000 x26: dead000000000100 [ 294.321980] x25: dead000000000200 x24: ffff803f6bd06800 [ 294.327366] x23: 0000000000000000 x22: 0000000000000000 [ 294.332752] x21: ffff00001001bd04 x20: ffff80df33d19018 [ 294.338137] x19: ffff80df33d19018 x18: 0000000000000000 [ 294.343523] x17: 0000000000000000 x16: 0000000000000000 [ 294.348908] x15: 0000000000000000 x14: 0000000000000002 [ 294.354293] x13: 0000000000000000 x12: 0000000000000000 [ 294.359679] x11: 0000000000000000 x10: 0000000000100000 [ 294.365065] x9 : 0000000000000000 x8 : 0000000000000004 [ 294.370451] x7 : 0000000000000000 x6 : ffff80df34558678 [ 294.375836] x5 : 000000000000000c x4 : 0000000000000000 [ 294.381221] x3 : 0000000000000001 x2 : 0000803fea6ea000 [ 294.386607] x1 : 0000803fea6ea008 x0 : 0000000000000001 [ 294.391994] Process swapper/3 (pid: 0, stack limit = 0x0000000083087293) [ 294.398791] Call trace: [ 294.401266] __srcu_read_lock+0x38/0x58 [ 294.405154] acquire_ipmi_user+0x2c/0x70 [ipmi_msghandler] [ 294.410716] deliver_response+0x80/0xf8 [ipmi_msghandler] [ 294.416189] deliver_local_response+0x28/0x68 [ipmi_msghandler] [ 294.422193] handle_one_recv_msg+0x158/0xcf8 [ipmi_msghandler] [ 294.432050] handle_new_recv_msgs+0xc0/0x210 [ipmi_msghandler] [ 294.441984] smi_recv_tasklet+0x8c/0x158 [ipmi_msghandler] [ 294.451618] tasklet_action_common.isra.5+0x88/0x138 [ 294.460661] tasklet_action+0x2c/0x38 [ 294.468191] __do_softirq+0x120/0x2f8 [ 294.475561] irq_exit+0x134/0x140 [ 294.482445] __handle_domain_irq+0x6c/0xc0 [ 294.489954] gic_handle_irq+0xb8/0x178 [ 294.497037] el1_irq+0xb0/0x140 [ 294.503381] arch_cpu_idle+0x34/0x1a8 [ 294.510096] do_idle+0x1d4/0x290 [ 294.516322] cpu_startup_entry+0x28/0x30 [ 294.523230] secondary_start_kernel+0x184/0x1d0 [ 294.530657] Code: d538d082 d2800023 8b010c81 8b020021 (c85f7c25) [ 294.539746] ---[ end trace 8a7a880dee570b29 ]--- [ 294.547341] Kernel panic - not syncing: Fatal exception in interrupt [ 294.556837] SMP: stopping secondary CPUs [ 294.563996] Kernel Offset: disabled [ 294.570515] CPU features: 0x002,21006008 [ 294.577638] Memory Limit: none [ 294.587178] Starting crashdump kernel... [ 294.594314] Bye! Because the user->release_barrier.rda is freed in ipmi_destroy_user(), but the refcount is not zero, when acquire_ipmi_user() uses user->release_barrier.rda in __srcu_read_lock(), it causes oops. Fix this by calling cleanup_srcu_struct() when the refcount is zero. Fixes: e86ee2d44b44 ("ipmi: Rework locking and shutdown for hot remove") Cc: stable@vger.kernel.org # 4.18 Signed-off-by: Yang Yingliang Signed-off-by: Corey Minyard --- drivers/char/ipmi/ipmi_msghandler.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index cc5665c47a0e..e43c27ff59b4 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -1184,6 +1184,7 @@ EXPORT_SYMBOL(ipmi_get_smi_info); static void free_user(struct kref *ref) { struct ipmi_user *user = container_of(ref, struct ipmi_user, refcount); + cleanup_srcu_struct(&user->release_barrier); kfree(user); } @@ -1260,7 +1261,6 @@ int ipmi_destroy_user(struct ipmi_user *user) { _ipmi_destroy_user(user); - cleanup_srcu_struct(&user->release_barrier); kref_put(&user->refcount, free_user); return 0; -- 2.30.2