Messages in this thread | | | Subject | Re: memory leak in pty_common_install | From | Jiri Slaby <> | Date | Fri, 2 Aug 2019 08:23:25 +0200 |
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On 30. 07. 19, 17:08, syzbot wrote: > 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
So this is tty_port for o_tty.
...
> 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
And this is o_tty proper. So we leak whole o_tty under some circumstances... Trying to reproduce.
BTW the reproducer says: ioctl$TCSETS(r0, 0x40045431, ...)
But 0x40045431 is TIOCSPTLCK, not TCSETS.
thanks, -- js suse labs
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