From 9ac0be9d4fa0c0ec7a447eeaa080bc13cf865319 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Tue, 14 Aug 2007 17:24:05 -0700 Subject: [PATCH] [AX25]: don't free pointers to statically allocated data commit 8d5cf596d10d740b69b5f4bbdb54b85abf75810d started to add statically allocated ax25_protocol's to list. However kfree() was still in place waiting for unsuspecting ones on module removal. Steps to reproduce: modprobe netrom rmmod netrom P.S.: code would benefit greatly from list_add/list_del usage kernel BUG at mm/slab.c:592! invalid opcode: 0000 [1] PREEMPT SMP CPU 0 Modules linked in: netrom ax25 af_packet usbcore rtc_cmos rtc_core rtc_lib Pid: 4477, comm: rmmod Not tainted 2.6.23-rc3-bloat #2 RIP: 0010:[] [] kfree+0x1c6/0x260 RSP: 0000:ffff810079a05e48 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff81000000c000 RDX: ffff81007e552458 RSI: 0000000000000000 RDI: 000000000000805d RBP: ffff810079a05e88 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8805d080 R13: ffffffff8805d080 R14: 0000000000000000 R15: 0000000000000282 FS: 00002b73fc98aae0(0000) GS:ffffffff805dc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 000000000053f3b8 CR3: 0000000079ff2000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process rmmod (pid: 4477, threadinfo ffff810079a04000, task ffff8100775aa480) Stack: ffff810079a05e68 0000000000000246 ffffffff8804eca0 0000000000000000 ffffffff8805d080 00000000000000cf 0000000000000000 0000000000000880 ffff810079a05eb8 ffffffff8803ec90 ffff810079a05eb8 0000000000000000 Call Trace: [] :ax25:ax25_protocol_release+0xa0/0xb0 [] :netrom:nr_exit+0x6b/0xf0 [] sys_delete_module+0x170/0x1f0 [] trace_hardirqs_on+0xd5/0x170 [] trace_hardirqs_on_thunk+0x35/0x37 [] system_call+0x7e/0x83 Code: 0f 0b eb fe 66 66 90 66 66 90 48 8b 52 10 48 8b 02 25 00 40 RIP [] kfree+0x1c6/0x260 RSP Kernel panic - not syncing: Fatal exception Signed-off-by: Alexey Dobriyan Signed-off-by: David S. Miller --- net/ax25/ax25_iface.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/net/ax25/ax25_iface.c b/net/ax25/ax25_iface.c index 16be0c14780a..8443af57a374 100644 --- a/net/ax25/ax25_iface.c +++ b/net/ax25/ax25_iface.c @@ -69,7 +69,6 @@ void ax25_protocol_release(unsigned int pid) if (protocol->pid == pid) { protocol_list = protocol->next; write_unlock_bh(&protocol_list_lock); - kfree(protocol); return; } @@ -78,7 +77,6 @@ void ax25_protocol_release(unsigned int pid) s = protocol->next; protocol->next = protocol->next->next; write_unlock_bh(&protocol_list_lock); - kfree(s); return; } -- 2.20.1