[PATCH] char: mxser.c, tty->driver_data is not set, kernel 2.6.33.7
in [Kernel]
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From: Alexander on 10 Aug 2010 10:40 Hello, tty->driver_data is not initialized in drivers/char/mxser.c, so it results in something like this: BUG: unable to handle kernel NULL pointer dereference at 0000007c IP: [<d098753f>] mxser_change_speed+0x1f/0x5e0 [mxser] .... Pid: 1662, comm: msterm Not tainted 2.6.33.4-smp #1 nVidia-nForce/ EIP: 0060:[<d098753f>] EFLAGS: 00010092 CPU: 0 EIP is at mxser_change_speed+0x1f/0x5e0 [mxser] EAX: cb0b1840 EBX: 00000000 ECX: 0000c400 EDX: cb263800 ESI: 00000cbd EDI: cb263800 EBP: cf9a3dc0 ESP: cf9a3d7c DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 Process msterm (pid: 1662, ti=cf9a2000 task=cf930000 task.ti=cf9a2000) Stack: 00000000 cb263800 cb0ec000 00000001 00000003 c16274d0 c16274cc 00000001 <0> 00000292 cf9a3dc0 c1647740 d098b5bc d098b5bc cb263800 0000c405 d098b5bc <0> cb263800 cf9a3de8 d0987e4e d098b5a0 d098b6fc 0000c406 0000c402 00000286 Call Trace: [<d0987e4e>] ? mxser_activate+0x12e/0x1b0 [mxser] [<c129d5df>] ? tty_port_open+0x6f/0xb0 [<d0988306>] ? mxser_open+0x76/0x80 [mxser] [<c12970fc>] ? tty_open+0x22c/0x510 [<c10dee4b>] ? chrdev_open+0xbb/0x1a0 [<c105f0aa>] ? in_group_p+0x2a/0x30 [<c10d9e53>] ? __dentry_open+0xe3/0x290 [<c10e3f73>] ? inode_permission+0x83/0xb0 [<c10db04a>] ? nameidata_to_filp+0x4a/0x60 [<c10ded90>] ? chrdev_open+0x0/0x1a0 [<c10e732a>] ? do_filp_open+0x6fa/0x9b0 [<c1057b5d>] ? remove_wait_queue+0x3d/0x50 [<c129bb4d>] ? tty_ldisc_deref+0xd/0x10 [<c12961f7>] ? tty_write+0x1b7/0x1e0 [<c10f0de4>] ? alloc_fd+0x74/0x100 [<c10d9c06>] ? do_sys_open+0x56/0x110 [<c10d9d2e>] ? sys_open+0x2e/0x40 [<c1471874>] ? syscall_call+0x7/0xb Code: b6 00 00 00 00 8d bc 27 00 00 00 00 55 89 e5 57 56 53 83 ec 38 0f 1f 44 00 00 89 45 c0 89 c2 8b 98 3c 01 00 00 8b 40 44 8b 70 08 <8b> 43 7c 85 c0 0f 84 bc 01 00 00 8b 42 10 8b 04 85 c0 df 98 d0 EIP: [<d098753f>] mxser_change_speed+0x1f/0x5e0 [mxser] SS:ESP 0068:cf9a3d7c CR2: 000000000000007c In kernels 2.6.34 and up it's fixed already, but not in 2.6.33.7. The included patch is against 2.6.33.7: --- linux-2.6.33.7/drivers/char/mxser.c 2010-08-02 20:27:18.000000000 +0300 +++ my-linux-2.6.33.7/drivers/char/mxser.c 2010-08-10 15:14:01.000000000 +0300 @@ -1012,6 +1012,8 @@ if (!info->ioaddr) return -ENODEV; + tty->driver_data = info; + return tty_port_open(&info->port, tty, filp); } -- Alexander Pravdin aledin(a)evpatoria.com.ua -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |