From 891e6a931255238dddd08a7b306871240961a27f Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Sun, 7 Oct 2007 23:44:17 -0700 Subject: [PATCH] [ROSE]: Fix rose.ko oops on unload Commit a3d384029aa304f8f3f5355d35f0ae274454f7cd aka "[AX.25]: Fix unchecked rose_add_loopback_neigh uses" transformed rose_loopback_neigh var into statically allocated one. However, on unload it will be kfree's which can't work. Steps to reproduce: modprobe rose rmmod rose BUG: unable to handle kernel NULL pointer dereference at virtual address 00000008 printing eip: c014c664 *pde = 00000000 Oops: 0000 [#1] PREEMPT DEBUG_PAGEALLOC Modules linked in: rose ax25 fan ufs loop usbhid rtc snd_intel8x0 snd_ac97_codec ehci_hcd ac97_bus uhci_hcd thermal usbcore button processor evdev sr_mod cdrom CPU: 0 EIP: 0060:[] Not tainted VLI EFLAGS: 00210086 (2.6.23-rc9 #3) EIP is at kfree+0x48/0xa1 eax: 00000556 ebx: c1734aa0 ecx: f6a5e000 edx: f7082000 esi: 00000000 edi: f9a55d20 ebp: 00200287 esp: f6a5ef28 ds: 007b es: 007b fs: 0000 gs: 0033 ss: 0068 Process rmmod (pid: 1823, ti=f6a5e000 task=f7082000 task.ti=f6a5e000) Stack: f9a55d20 f9a5200c 00000000 00000000 00000000 f6a5e000 f9a5200c f9a55a00 00000000 bf818cf0 f9a51f3f f9a55a00 00000000 c0132c60 65736f72 00000000 f69f9630 f69f9528 c014244a f6a4e900 00200246 f7082000 c01025e6 00000000 Call Trace: [] rose_rt_free+0x1d/0x49 [rose] [] rose_rt_free+0x1d/0x49 [rose] [] rose_exit+0x4c/0xd5 [rose] [] sys_delete_module+0x15e/0x186 [] remove_vma+0x40/0x45 [] sysenter_past_esp+0x8f/0x99 [] trace_hardirqs_on+0x118/0x13b [] sysenter_past_esp+0x5f/0x99 ======================= Code: 05 03 1d 80 db 5b c0 8b 03 25 00 40 02 00 3d 00 40 02 00 75 03 8b 5b 0c 8b 73 10 8b 44 24 18 89 44 24 04 9c 5d fa e8 77 df fd ff <8b> 56 08 89 f8 e8 84 f4 fd ff e8 bd 32 06 00 3b 5c 86 60 75 0f EIP: [] kfree+0x48/0xa1 SS:ESP 0068:f6a5ef28 Signed-off-by: Alexey Dobriyan Signed-off-by: David S. Miller --- include/net/rose.h | 2 +- net/rose/rose_loopback.c | 4 ++-- net/rose/rose_route.c | 15 ++++++++++----- 3 files changed, 13 insertions(+), 8 deletions(-) diff --git a/include/net/rose.h b/include/net/rose.h index a4047d3cf5d..e5bb084d875 100644 --- a/include/net/rose.h +++ b/include/net/rose.h @@ -188,7 +188,7 @@ extern void rose_kick(struct sock *); extern void rose_enquiry_response(struct sock *); /* rose_route.c */ -extern struct rose_neigh rose_loopback_neigh; +extern struct rose_neigh *rose_loopback_neigh; extern const struct file_operations rose_neigh_fops; extern const struct file_operations rose_nodes_fops; extern const struct file_operations rose_routes_fops; diff --git a/net/rose/rose_loopback.c b/net/rose/rose_loopback.c index cd01642f049..114df6eec8c 100644 --- a/net/rose/rose_loopback.c +++ b/net/rose/rose_loopback.c @@ -79,7 +79,7 @@ static void rose_loopback_timer(unsigned long param) skb_reset_transport_header(skb); - sk = rose_find_socket(lci_o, &rose_loopback_neigh); + sk = rose_find_socket(lci_o, rose_loopback_neigh); if (sk) { if (rose_process_rx_frame(sk, skb) == 0) kfree_skb(skb); @@ -88,7 +88,7 @@ static void rose_loopback_timer(unsigned long param) if (frametype == ROSE_CALL_REQUEST) { if ((dev = rose_dev_get(dest)) != NULL) { - if (rose_rx_call_request(skb, dev, &rose_loopback_neigh, lci_o) == 0) + if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0) kfree_skb(skb); } else { kfree_skb(skb); diff --git a/net/rose/rose_route.c b/net/rose/rose_route.c index bbcbad1da0d..96f61a71b25 100644 --- a/net/rose/rose_route.c +++ b/net/rose/rose_route.c @@ -45,7 +45,7 @@ static DEFINE_SPINLOCK(rose_neigh_list_lock); static struct rose_route *rose_route_list; static DEFINE_SPINLOCK(rose_route_list_lock); -struct rose_neigh rose_loopback_neigh; +struct rose_neigh *rose_loopback_neigh; /* * Add a new route to a node, and in the process add the node and the @@ -362,7 +362,12 @@ out: */ void rose_add_loopback_neigh(void) { - struct rose_neigh *sn = &rose_loopback_neigh; + struct rose_neigh *sn; + + rose_loopback_neigh = kmalloc(sizeof(struct rose_neigh), GFP_KERNEL); + if (!rose_loopback_neigh) + return; + sn = rose_loopback_neigh; sn->callsign = null_ax25_address; sn->digipeat = NULL; @@ -417,13 +422,13 @@ int rose_add_loopback_node(rose_address *address) rose_node->mask = 10; rose_node->count = 1; rose_node->loopback = 1; - rose_node->neighbour[0] = &rose_loopback_neigh; + rose_node->neighbour[0] = rose_loopback_neigh; /* Insert at the head of list. Address is always mask=10 */ rose_node->next = rose_node_list; rose_node_list = rose_node; - rose_loopback_neigh.count++; + rose_loopback_neigh->count++; out: spin_unlock_bh(&rose_node_list_lock); @@ -454,7 +459,7 @@ void rose_del_loopback_node(rose_address *address) rose_remove_node(rose_node); - rose_loopback_neigh.count--; + rose_loopback_neigh->count--; out: spin_unlock_bh(&rose_node_list_lock); -- 2.20.1