Messages in this thread Patch in this message | | | From | Arnd Bergmann <> | Subject | [PATCH v2] udf: avoid uninitialized variable use | Date | Fri, 01 Jan 2016 15:21:54 +0100 |
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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.
diff --git a/fs/udf/inode.c b/fs/udf/inode.c index 5b83351041a4..42f68dd7e6ef 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -1890,6 +1890,8 @@ int udf_setup_indirect_aext(struct inode *inode, int block, adsize = sizeof(struct short_ad); else if (UDF_I(inode)->i_alloc_type == ICBTAG_FLAG_AD_LONG) adsize = sizeof(struct long_ad); + else + adsize = 0; neloc.logicalBlockNum = block; neloc.partitionReferenceNum = epos->block.partitionReferenceNum; @@ -1963,6 +1965,8 @@ int __udf_add_aext(struct inode *inode, struct extent_position *epos, adsize = sizeof(struct short_ad); else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG) adsize = sizeof(struct long_ad); + else + adsize = 0; if (!epos->bh) { WARN_ON(iinfo->i_lenAlloc !=
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