Re: [PATCH] fs: affs: fix a NULL pointer dereference
From: kbuild test robot
Date: Thu Mar 14 2019 - 10:52:49 EST
Hi Kangjie,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v5.0 next-20190306]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Kangjie-Lu/fs-affs-fix-a-NULL-pointer-dereference/20190314-170334
reproduce:
# apt-get install sparse
make ARCH=x86_64 allmodconfig
make C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'
sparse warnings: (new ones prefixed by >>)
fs/affs/file.c:525:23: sparse: expression using sizeof(void)
fs/affs/file.c:525:23: sparse: expression using sizeof(void)
fs/affs/file.c:558:23: sparse: expression using sizeof(void)
fs/affs/file.c:558:23: sparse: expression using sizeof(void)
fs/affs/file.c:577:23: sparse: expression using sizeof(void)
fs/affs/file.c:577:23: sparse: expression using sizeof(void)
fs/affs/file.c:706:23: sparse: expression using sizeof(void)
fs/affs/file.c:706:23: sparse: expression using sizeof(void)
fs/affs/file.c:759:23: sparse: expression using sizeof(void)
fs/affs/file.c:759:23: sparse: expression using sizeof(void)
>> fs/affs/file.c:946:40: sparse: incorrect type in assignment (different base types) @@ expected unsigned int [unsigned] [usertype] ext_bk @@ got igned] [usertype] ext_bk @@
fs/affs/file.c:946:40: expected unsigned int [unsigned] [usertype] ext_bk
fs/affs/file.c:946:40: got restricted __be32 <noident>
>> fs/affs/file.c:947:53: sparse: cast to restricted __be32
>> fs/affs/file.c:947:53: sparse: cast to restricted __be32
>> fs/affs/file.c:947:53: sparse: cast to restricted __be32
>> fs/affs/file.c:947:53: sparse: cast to restricted __be32
>> fs/affs/file.c:947:53: sparse: cast to restricted __be32
>> fs/affs/file.c:947:53: sparse: cast to restricted __be32
vim +946 fs/affs/file.c
833
834 void
835 affs_truncate(struct inode *inode)
836 {
837 struct super_block *sb = inode->i_sb;
838 u32 ext, ext_key, ext_bk;
839 u32 last_blk, blkcnt, blk;
840 u32 size;
841 struct buffer_head *ext_bh;
842 int i;
843
844 pr_debug("truncate(inode=%lu, oldsize=%llu, newsize=%llu)\n",
845 inode->i_ino, AFFS_I(inode)->mmu_private, inode->i_size);
846
847 last_blk = 0;
848 ext = 0;
849 if (inode->i_size) {
850 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
851 ext = last_blk / AFFS_SB(sb)->s_hashsize;
852 }
853
854 if (inode->i_size > AFFS_I(inode)->mmu_private) {
855 struct address_space *mapping = inode->i_mapping;
856 struct page *page;
857 void *fsdata;
858 loff_t isize = inode->i_size;
859 int res;
860
861 res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, 0, &page, &fsdata);
862 if (!res)
863 res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata);
864 else
865 inode->i_size = AFFS_I(inode)->mmu_private;
866 mark_inode_dirty(inode);
867 return;
868 } else if (inode->i_size == AFFS_I(inode)->mmu_private)
869 return;
870
871 // lock cache
872 ext_bh = affs_get_extblock(inode, ext);
873 if (IS_ERR(ext_bh)) {
874 affs_warning(sb, "truncate",
875 "unexpected read error for ext block %u (%ld)",
876 ext, PTR_ERR(ext_bh));
877 return;
878 }
879 if (AFFS_I(inode)->i_lc) {
880 /* clear linear cache */
881 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
882 if (AFFS_I(inode)->i_lc_size > i) {
883 AFFS_I(inode)->i_lc_size = i;
884 for (; i < AFFS_LC_SIZE; i++)
885 AFFS_I(inode)->i_lc[i] = 0;
886 }
887 /* clear associative cache */
888 for (i = 0; i < AFFS_AC_SIZE; i++)
889 if (AFFS_I(inode)->i_ac[i].ext >= ext)
890 AFFS_I(inode)->i_ac[i].ext = 0;
891 }
892 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
893
894 blkcnt = AFFS_I(inode)->i_blkcnt;
895 i = 0;
896 blk = last_blk;
897 if (inode->i_size) {
898 i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
899 blk++;
900 } else
901 AFFS_HEAD(ext_bh)->first_data = 0;
902 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i);
903 size = AFFS_SB(sb)->s_hashsize;
904 if (size > blkcnt - blk + i)
905 size = blkcnt - blk + i;
906 for (; i < size; i++, blk++) {
907 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
908 AFFS_BLOCK(sb, ext_bh, i) = 0;
909 }
910 AFFS_TAIL(sb, ext_bh)->extension = 0;
911 affs_fix_checksum(sb, ext_bh);
912 mark_buffer_dirty_inode(ext_bh, inode);
913 affs_brelse(ext_bh);
914
915 if (inode->i_size) {
916 AFFS_I(inode)->i_blkcnt = last_blk + 1;
917 AFFS_I(inode)->i_extcnt = ext + 1;
918 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS)) {
919 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
920 u32 tmp;
921 if (IS_ERR(bh)) {
922 affs_warning(sb, "truncate",
923 "unexpected read error for last block %u (%ld)",
924 ext, PTR_ERR(bh));
925 return;
926 }
927 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
928 AFFS_DATA_HEAD(bh)->next = 0;
929 affs_adjust_checksum(bh, -tmp);
930 affs_brelse(bh);
931 }
932 } else {
933 AFFS_I(inode)->i_blkcnt = 0;
934 AFFS_I(inode)->i_extcnt = 1;
935 }
936 AFFS_I(inode)->mmu_private = inode->i_size;
937 // unlock cache
938
939 while (ext_key) {
940 ext_bh = affs_bread(sb, ext_key);
941 size = AFFS_SB(sb)->s_hashsize;
942 if (size > blkcnt - blk)
943 size = blkcnt - blk;
944 if (ext_bh) {
945 for (i = 0; i < size; i++, blk++) {
> 946 ext_bk = AFFS_BLOCK(sb, ext_bh, i);
> 947 affs_free_block(sb, be32_to_cpu(ext_bk));
948 }
949 }
950 affs_free_block(sb, ext_key);
951 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
952 affs_brelse(ext_bh);
953 }
954 affs_free_prealloc(inode);
955 }
956
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