пн, 9 сент. 2019 г. в 05:46, Aurélien Aptel <aaptel@xxxxxxxx>:
>
> " Paulo Alcantara (SUSE) " <paulo@xxxxxxxx> writes:
> > It can be easily reproduced with the following:
> >
> > # chmod +s `which mount.cifs`
> > # echo "//localhost/share /mnt cifs \
> > users,username=foo,password=XXXX" >> /etc/fstab
> > # su - foo
> > $ mount /mnt
> > free(): double free detected in tcache 2
> > Child process terminated abnormally.
> >
> > The problem was that check_fstab() already freed orgoptions pointer
> > and then we freed it again in main() function.
> >
> > Fixes: bf7f48f4c7dc ("mount.cifs.c: fix memory leaks in main func")
> > Signed-off-by: Paulo Alcantara (SUSE) <paulo@xxxxxxxx>
>
> Reviewed-by: Aurelien Aptel <aaptel@xxxxxxxx>
>
> I've compiled next branch with ASAN and can confirm the double-free and
> the fix works
>
> Compiling with ASAN
> -------------------
>
> $ CFLAGS=-fsanitize=address \
> LDFLAGS=-fsanitize=address \
> ac_cv_func_malloc_0_nonnull=yes \
> ./configure
> $ make clean && make -j4
>
> Next branch
> -----------
>
> $ mount /mnt; echo $?
> =================================================================
> ==29883==ERROR: AddressSanitizer: attempting double-free on 0x607000000020 in thread T0:
> #0 0x7f69d480a1b8 in __interceptor_free (/usr/lib64/libasan.so.4+0xdc1b8)
> #1 0x559381795f33 in main (/sbin/mount.cifs+0xef33)
> #2 0x7f69d4394f89 in __libc_start_main (/lib64/libc.so.6+0x20f89)
> #3 0x55938178e079 in _start (/sbin/mount.cifs+0x7079)
>
> 0x607000000020 is located 0 bytes inside of 68-byte region [0x607000000020,0x607000000064)
> freed by thread T0 here:
> #0 0x7f69d480a1b8 in __interceptor_free (/usr/lib64/libasan.so.4+0xdc1b8)
> #1 0x55938178e372 in check_fstab (/sbin/mount.cifs+0x7372)
> #2 0x559381794661 in assemble_mountinfo (/sbin/mount.cifs+0xd661)
> #3 0x559381795eef in main (/sbin/mount.cifs+0xeeef)
> #4 0x7f69d4394f89 in __libc_start_main (/lib64/libc.so.6+0x20f89)
>
> previously allocated by thread T0 here:
> #0 0x7f69d480a510 in malloc (/usr/lib64/libasan.so.4+0xdc510)
> #1 0x7f69d43fc2a9 in __GI___strndup (/lib64/libc.so.6+0x882a9)
>
> SUMMARY: AddressSanitizer: double-free (/usr/lib64/libasan.so.4+0xdc1b8) in __interceptor_free
> ==29883==ABORTING
> 1
>
> With fix
> --------
>
> $ mount /mnt; echo $?
> 0
>
> Cheers,
> --
> Aurélien Aptel / SUSE Labs Samba Team
> GPG: 1839 CB5F 9F5B FB9B AA97 8C99 03C8 A49B 521B D5D3
> SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg, DE
> GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 247165 (AG München)
Merged, thanks.
--
Best regards,
Pavel Shilovsky
