Messages in this thread | | | Subject | Re: memory leak in pty_common_install | From | Jiri Slaby <> | Date | Mon, 5 Aug 2019 11:11:00 +0200 |
| |
On 04. 08. 19, 16:23, Hillf Danton wrote: > > On Tue, 30 Jul 2019 08:08:05 -0700 >> Hello, >> >> syzbot found the following crash on: >> >> HEAD commit: 6789f873 Merge tag 'pm-5.3-rc2' of git://git.kernel.org/pu.. >> git tree: upstream >> console output: https://syzkaller.appspot.com/x/log.txt?x=1696897c600000 >> kernel config: https://syzkaller.appspot.com/x/.config?x=339b6a6b3640d115 >> dashboard link: https://syzkaller.appspot.com/bug?extid=bdebcbf44250d75bdd82 >> compiler: gcc (GCC) 9.0.0 20181231 (experimental) >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=153d7544600000 >> >> IMPORTANT: if you fix the bug, please add the following tag to the commit: >> Reported-by: syzbot+bdebcbf44250d75bdd82@syzkaller.appspotmail.com >> >> BUG: memory leak >> unreferenced object 0xffff88810d84d400 (size 512): >> comm "syz-executor.5", pid 7522, jiffies 4294954305 (age 14.260s) >> hex dump (first 32 bytes): >> 50 d4 84 0d 81 88 ff ff e0 ff ff ff 0f 00 00 00 P............... >> 10 d4 84 0d 81 88 ff ff 10 d4 84 0d 81 88 ff ff ................ >> backtrace: >> [<000000003d61da44>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] >> [<000000003d61da44>] slab_post_alloc_hook mm/slab.h:522 [inline] >> [<000000003d61da44>] slab_alloc mm/slab.c:3319 [inline] >> [<000000003d61da44>] kmem_cache_alloc_trace+0x145/0x2c0 mm/slab.c:3548 >> [<00000000a6239e0a>] kmalloc include/linux/slab.h:552 [inline] >> [<00000000a6239e0a>] pty_common_install+0x4e/0x2b0 drivers/tty/pty.c:391 >> [<00000000bd8cb19d>] pty_unix98_install+0x20/0x30 drivers/tty/pty.c:740 >> [<000000001b46b5e1>] tty_driver_install_tty drivers/tty/tty_io.c:1227 [inline] >> [<000000001b46b5e1>] tty_init_dev drivers/tty/tty_io.c:1340 [inline] >> [<000000001b46b5e1>] tty_init_dev+0x86/0x210 drivers/tty/tty_io.c:1317 >> [<00000000845ae712>] ptmx_open drivers/tty/pty.c:845 [inline] >> [<00000000845ae712>] ptmx_open+0xba/0x1c0 drivers/tty/pty.c:811 >> [<000000007e87d771>] chrdev_open+0xe3/0x290 fs/char_dev.c:414 >> [<00000000bd556826>] do_dentry_open+0x199/0x4f0 fs/open.c:797 >> [<000000001ba9145b>] vfs_open+0x35/0x40 fs/open.c:906 >> [<00000000c0275eb4>] do_last fs/namei.c:3416 [inline] >> [<00000000c0275eb4>] path_openat+0x854/0x1cd0 fs/namei.c:3533 >> [<00000000156ad8b1>] do_filp_open+0xaa/0x130 fs/namei.c:3563 >> [<00000000074d96c0>] do_sys_open+0x253/0x330 fs/open.c:1089 >> [<000000009f7fc64a>] __do_sys_openat fs/open.c:1116 [inline] >> [<000000009f7fc64a>] __se_sys_openat fs/open.c:1110 [inline] >> [<000000009f7fc64a>] __x64_sys_openat+0x24/0x30 fs/open.c:1110 >> [<000000005ca4479f>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:296 >> [<00000000e1f64b0f>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 >> >> BUG: memory leak >> unreferenced object 0xffff88810e639800 (size 1024): >> comm "syz-executor.5", pid 7522, jiffies 4294954305 (age 14.260s) >> hex dump (first 32 bytes): >> 01 54 00 00 01 00 00 00 00 00 00 00 00 00 00 00 .T.............. >> 00 83 fa 19 82 88 ff ff a0 7f 9b 83 ff ff ff ff ................ >> backtrace: >> [<000000003d61da44>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] >> [<000000003d61da44>] slab_post_alloc_hook mm/slab.h:522 [inline] >> [<000000003d61da44>] slab_alloc mm/slab.c:3319 [inline] >> [<000000003d61da44>] kmem_cache_alloc_trace+0x145/0x2c0 mm/slab.c:3548 >> [<000000001cfffc30>] kmalloc include/linux/slab.h:552 [inline] >> [<000000001cfffc30>] kzalloc include/linux/slab.h:748 [inline] >> [<000000001cfffc30>] alloc_tty_struct+0x3f/0x290 drivers/tty/tty_io.c:2981 >> [<000000001946a70c>] pty_common_install+0xac/0x2b0 drivers/tty/pty.c:399 >> [<00000000bd8cb19d>] pty_unix98_install+0x20/0x30 drivers/tty/pty.c:740 >> [<000000001b46b5e1>] tty_driver_install_tty drivers/tty/tty_io.c:1227 [inline] >> [<000000001b46b5e1>] tty_init_dev drivers/tty/tty_io.c:1340 [inline] >> [<000000001b46b5e1>] tty_init_dev+0x86/0x210 drivers/tty/tty_io.c:1317 >> [<00000000845ae712>] ptmx_open drivers/tty/pty.c:845 [inline] >> [<00000000845ae712>] ptmx_open+0xba/0x1c0 drivers/tty/pty.c:811 >> [<000000007e87d771>] chrdev_open+0xe3/0x290 fs/char_dev.c:414 >> [<00000000bd556826>] do_dentry_open+0x199/0x4f0 fs/open.c:797 >> [<000000001ba9145b>] vfs_open+0x35/0x40 fs/open.c:906 >> [<00000000c0275eb4>] do_last fs/namei.c:3416 [inline] >> [<00000000c0275eb4>] path_openat+0x854/0x1cd0 fs/namei.c:3533 >> [<00000000156ad8b1>] do_filp_open+0xaa/0x130 fs/namei.c:3563 >> [<00000000074d96c0>] do_sys_open+0x253/0x330 fs/open.c:1089 >> [<000000009f7fc64a>] __do_sys_openat fs/open.c:1116 [inline] >> [<000000009f7fc64a>] __se_sys_openat fs/open.c:1110 [inline] >> [<000000009f7fc64a>] __x64_sys_openat+0x24/0x30 fs/open.c:1110 >> [<000000005ca4479f>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:296 >> [<00000000e1f64b0f>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > Reset tty for port if none cares the open result.
Could you elaborate on how tty_port_open affects ptys? I.e. how does this report relates to the change below?
And why do you think it is necessary at all? tty_port_close should take care of it.
> --- a/drivers/tty/tty_port.c > +++ b/drivers/tty/tty_port.c > @@ -669,6 +669,8 @@ EXPORT_SYMBOL_GPL(tty_port_install); > int tty_port_open(struct tty_port *port, struct tty_struct *tty, > struct file *filp) > { > + int retval = 0; > + > spin_lock_irq(&port->lock); > ++port->count; > spin_unlock_irq(&port->lock); > @@ -685,16 +687,18 @@ int tty_port_open(struct tty_port *port, > if (!tty_port_initialized(port)) { > clear_bit(TTY_IO_ERROR, &tty->flags); > if (port->ops->activate) { > - int retval = port->ops->activate(port, tty); > - if (retval) { > - mutex_unlock(&port->mutex); > - return retval; > - } > + retval = port->ops->activate(port, tty); > + if (retval) > + goto out; > } > tty_port_set_initialized(port, 1); > } > +out: > mutex_unlock(&port->mutex); > - return tty_port_block_til_ready(port, tty, filp); > + if (!retval) > + retval = tty_port_block_til_ready(port, tty, filp); > + if (retval) > + tty_port_tty_set(port, 0); > + return retval; > } > - > EXPORT_SYMBOL(tty_port_open); > -- > >
thanks, -- js suse labs
| |