Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH v2] udf: avoid uninitialized variable use | Date | Mon, 04 Jan 2016 11:46:28 +0100 |
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On Monday 04 January 2016 10:56:05 Jan Kara wrote: > On Fri 01-01-16 15:21:54, Arnd Bergmann wrote: > > A new warning about a real bug has come up from a recent cleanup: > > > > fs/udf/inode.c: In function 'udf_setup_indirect_aext': > > fs/udf/inode.c:1927:28: warning: 'adsize' may be used uninitialized in this function [-Wmaybe-uninitialized] > > > > If the alloc_type is neither ICBTAG_FLAG_AD_SHORT nor ICBTAG_FLAG_AD_LONG, > > the value of adsize is undefined. This changes the code to use zero for adsize > > in that case, which may be the correct solution, though I have not looked > > at the code in enough detail to know if it should be something else instead. > > > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > Fixes: fcea62babc81 ("udf: Factor out code for creating indirect extent") > > --- > > sorry for missing another instance the first time around. The warning is > > a bit unreliable and it seems in my first configuration I got it only > > for one of the two instances that show it in other configuration. > > > > After checking the remaining functions in this file for the same possible > > problem, I found that the other functions use either 'BUG()' or 'return -EIO' > > in the 'else' path, so I assume the two functions here should one of those > > as well, but I don't know which. > > Callers of these functions make sure alloc_type is one of the two valid > ones. However for future-proofing you're right that probably we should > handle the invalid case as well. Setting adsize to zero is problematic - > not sure what the code would actually do but it wouldn't definitely work. > I'd just return -EIO. Attached is the patch I have merged. > >
Looks good, thanks!
Arnd
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