New: ext4_fill_super() reports success even if ext4_mb_init() fails
https://bugzilla.kernel.org/show_bug.cgi?id=48431
Summary: ext4_fill_super() reports success even if
ext4_mb_init() fails
Product: File System
Version: 2.5
Kernel Version: 3.6
Platform: All
OS/Version: Linux
Tree: Mainline
Status: NEW
Severity: normal
Priority: P1
Component: ext4
AssignedTo: [email protected]
ReportedBy: [email protected]
Regression: No
Created an attachment (id=82361)
--> (https://bugzilla.kernel.org/attachment.cgi?id=82361)
The patch to fix the problem
If ext4_mb_init() called from ext4_fill_super() (fs/ext4/super.c:3980 in the current ext4 git tree) fails and returns error code, ext4_fill_super() still returns 0.
This happens because the return value of ext4_mb_init() is not assigned to 'ret' in the error path. So the previous value of 'ret' (0) is returned from ext4_fill_super().
This problem leads to a kernel oops in mount_fs() when the latter tries to access the struct dentry that the mount() callback returns ("sb = root->d_sb;" in fs/super.c:1180).
The problem has been revealed with the help of the fault simulation facilities provided by KEDR Framework.
Attached is a trivial patch that fixes the problem.
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PATCH 1/1 ext4_fill_super() reports success even if ext4_mb_init() fails
https://bugzilla.kernel.org/show_bug.cgi?id=48431
Alan <[email protected]> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |[email protected] Summary|ext4_fill_super() reports |[PATCH]ext4_fill_super() |success even if |reports success even if |ext4_mb_init() fails |ext4_mb_init() fails
--- Comment #1 from Alan <[email protected]> 2012-10-05 14:15:59 --- Patches should be sent with a Signed-off-by: line to the relevant list (See Documentation/SubmittingPatches)
In this case [email protected]
You don't need to be subscribed to submit to it.
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PATCH 1/1 ext4_fill_super() reports success even if ext4_mb_init() fails
In reply to [email protected]https://bugzilla.kernel.org/show_bug.cgi?id=48431
Florian Mickler <[email protected]> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |[email protected]
--- Comment #2 from Florian Mickler <[email protected]> 2012-12-22 09:29:55 --- A patch referencing this bug report has been merged in Linux v3.8-rc1:
commit 07aa2ea13814ea60d12f7330b6d5ccfdb0c3ba4d
Author: Lukas Czerner <[email protected]> Date: Thu Nov 8 15:16:54 2012 -0500
ext4: fix error handling in ext4_fill_super()
Signature · 3 lines
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PATCH 1/1 ext4_fill_super() reports success even if ext4_mb_init() fails
In reply to [email protected]https://bugzilla.kernel.org/show_bug.cgi?id=48431
Alan <[email protected]> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |CODE_FIXSignature · 3 lines
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