On Mon, 06 Dec 2010 20:12:34 +0100 Robbert Kouprie <robbert@xxxxxx> wrote: > Hi Jeff, > > Op 6-12-2010 13:15, Jeff Layton schreef: > > It's possible that cifs_mount will call cifs_build_path_to_root on a > > newly instantiated cifs_sb. In that case, it's likely that the > > master_tlink pointer has not yet been instantiated. > > > > Fix this by having cifs_build_path_to_root take a cifsTconInfo pointer > > as well, and have the caller pass that in. > > I still get an oops on 2.6.37-rc4-git5 with the patch applied: > > BUG: unable to handle kernel NULL pointer dereference at 0000001c > IP: [<f8fd533b>] cifs_sb_master_tcon+0x3/0x7 [cifs] > *pde = 00000000 > Oops: 0000 [#1] SMP > last sysfs file: /sys/devices/virtual/bdi/cifs-2/uevent > Modules linked in: hmac nls_utf8 cifs nls_base xfs exportfs loop > snd_pcm parport_pc parport tpm_tis tpm tpm_bios snd_timer snd soundcore > snd_page_alloc psmouse evdev pcspkr serio_raw i2c_piix4 i2c_core shpchp > container pci_hotplug processor thermal_sys ac button ext3 jbd mbcache > sd_mod crc_t10dif ide_cd_mod cdrom ata_generic ata_piix libata floppy > e1000 mptspi mptscsih mptbase scsi_transport_spi scsi_mod piix ide_core > [last unloaded: scsi_wait_scan] > > Pid: 1362, comm: ls Not tainted 2.6.37-rc4-git5 #2 440BX Desktop > Reference Platform/VMware Virtual Platform > EIP: 0060:[<f8fd533b>] EFLAGS: 00010286 CPU: 0 > EIP is at cifs_sb_master_tcon+0x3/0x7 [cifs] > EAX: 00000000 EBX: f7156800 ECX: 40000040 EDX: 00000002 > ESI: f7156800 EDI: f7156a00 EBP: 00000000 ESP: f72fddb0 > DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 > Process ls (pid: 1362, ti=f72fc000 task=f71379e0 task.ti=f72fc000) > Stack: > f8fe14f3 002c80d0 00000000 f7156a00 f7156800 00000000 00000000 f8fcc96b > 0000007f f7156838 f5073d80 f50ac840 f8ff9f30 f8fcc7fd f522b000 c10b8301 > f50ac900 f5073d80 00000000 f50ac900 f50ac900 f72fded4 00000000 f8febc6f > Call Trace: > [<f8fe14f3>] ? cifs_root_iget+0x1e/0x13f [cifs] > [<f8fcc96b>] ? cifs_do_mount+0x16e/0x247 [cifs] > [<f8fcc7fd>] ? cifs_do_mount+0x0/0x247 [cifs] > [<c10b8301>] ? vfs_kern_mount+0x9f/0x185 > [<f8febc6f>] ? cifs_dfs_follow_mountpoint+0x233/0x3cc [cifs] > [<c10bec73>] ? do_follow_link+0xb6/0x1b1 > [<c10bf000>] ? link_path_walk+0x292/0x372 > [<c10bf1a2>] ? path_walk+0x4f/0xae > [<c10bf2d3>] ? do_path_lookup+0x1f/0x69 > [<c10bfb70>] ? user_path_at+0x37/0x5f > [<c1098af9>] ? vma_prio_tree_insert+0x17/0x2d > [<c10b9981>] ? vfs_fstatat+0x2a/0x50 > [<c10b99e8>] ? vfs_lstat+0x13/0x15 > [<c10b99f9>] ? sys_lstat64+0xf/0x23 > [<c1052a04>] ? sys_futex+0xfe/0x112 > [<c10b500c>] ? filp_close+0x4e/0x54 > [<c127f54f>] ? do_page_fault+0x0/0x36b > [<c1002f9f>] ? sysenter_do_call+0x12/0x28 > Code: c8 59 5f 39 ee 0f 8c 49 ff ff ff 8b 44 24 60 65 33 05 14 00 00 00 > 74 05 e8 ef 9b 05 c8 83 c4 64 5b 5e 5f 5d c3 90 90 90 8b 40 08 <8b> 40 > 1c c3 55 89 c5 83 3d a4 47 3b c1 00 57 89 d7 56 89 ce 53 > EIP: [<f8fd533b>] cifs_sb_master_tcon+0x3/0x7 [cifs] SS:ESP 0068:f72fddb0 > CR2: 000000000000001c > ---[ end trace 61b6103d05293c43 ]--- > > Regards, > Robbert > -- > To unsubscribe from this list: send the line "unsubscribe linux-cifs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html Interesting...does this (untested) patch fix it? It may have to be "wiggled" into place depending on your tree. If so, I'm surprised no one has tripped over this before... ----------------[snip]-------------------- cifs: fix check of error return from is_path_accessable This function will return 0 if everything went ok. Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> --- fs/cifs/connect.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index bee397f..9fbe7c5 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2836,7 +2836,7 @@ remote_path_check: goto mount_fail_check; } rc = is_path_accessible(xid, tcon, cifs_sb, full_path); - if (rc != -EREMOTE) { + if (rc != 0 && rc != -EREMOTE) { kfree(full_path); goto mount_fail_check; } -- 1.7.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
