* [PATCH] fs: affs: fix a NULL pointer dereference
@ 2019-03-14 7:46 Kangjie Lu
2019-03-14 14:51 ` kbuild test robot
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Kangjie Lu @ 2019-03-14 7:46 UTC (permalink / raw)
To: kjlu; +Cc: pakki001, David Sterba, linux-fsdevel, linux-kernel
If affs_bread fails, do not use ext_bh to avoid NULL pointer
dereference
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
---
fs/affs/file.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/fs/affs/file.c b/fs/affs/file.c
index a85817f54483..45b96faa40f1 100644
--- a/fs/affs/file.c
+++ b/fs/affs/file.c
@@ -835,7 +835,7 @@ void
affs_truncate(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
- u32 ext, ext_key;
+ u32 ext, ext_key, ext_bk;
u32 last_blk, blkcnt, blk;
u32 size;
struct buffer_head *ext_bh;
@@ -941,8 +941,12 @@ affs_truncate(struct inode *inode)
size = AFFS_SB(sb)->s_hashsize;
if (size > blkcnt - blk)
size = blkcnt - blk;
- for (i = 0; i < size; i++, blk++)
- affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
+ if (ext_bh) {
+ for (i = 0; i < size; i++, blk++) {
+ ext_bk = AFFS_BLOCK(sb, ext_bh, i);
+ affs_free_block(sb, be32_to_cpu(ext_bk));
+ }
+ }
affs_free_block(sb, ext_key);
ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
affs_brelse(ext_bh);
--
2.17.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] fs: affs: fix a NULL pointer dereference
2019-03-14 7:46 [PATCH] fs: affs: fix a NULL pointer dereference Kangjie Lu
@ 2019-03-14 14:51 ` kbuild test robot
2019-03-19 9:00 ` Dan Carpenter
2019-03-19 13:43 ` Geert Uytterhoeven
2 siblings, 0 replies; 6+ messages in thread
From: kbuild test robot @ 2019-03-14 14:51 UTC (permalink / raw)
To: Kangjie Lu
Cc: kbuild-all, kjlu, pakki001, David Sterba, linux-fsdevel, linux-kernel
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
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] fs: affs: fix a NULL pointer dereference
2019-03-14 7:46 [PATCH] fs: affs: fix a NULL pointer dereference Kangjie Lu
2019-03-14 14:51 ` kbuild test robot
@ 2019-03-19 9:00 ` Dan Carpenter
2019-03-19 13:43 ` Geert Uytterhoeven
2 siblings, 0 replies; 6+ messages in thread
From: Dan Carpenter @ 2019-03-19 9:00 UTC (permalink / raw)
To: kbuild, Kangjie Lu
Cc: kbuild-all, kjlu, pakki001, David Sterba, linux-fsdevel, linux-kernel
Hi Kangjie,
Thank you for the patch! Perhaps something to improve:
url: https://github.com/0day-ci/linux/commits/Kangjie-Lu/fs-affs-fix-a-NULL-pointer-dereference/20190314-170334
New smatch warnings:
fs/affs/file.c:951 affs_truncate() error: we previously assumed 'ext_bh' could be null (see line 944)
Old smatch warnings:
fs/affs/file.c:806 affs_write_end_ofs() warn: passing zero to 'PTR_ERR'
# https://github.com/0day-ci/linux/commit/2ee20c56bd586ddaf3ebdb1c3cad26439edc9eb6
git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout 2ee20c56bd586ddaf3ebdb1c3cad26439edc9eb6
vim +/ext_bh +951 fs/affs/file.c
^1da177e4 Linus Torvalds 2005-04-16 833
^1da177e4 Linus Torvalds 2005-04-16 834 void
^1da177e4 Linus Torvalds 2005-04-16 835 affs_truncate(struct inode *inode)
^1da177e4 Linus Torvalds 2005-04-16 836 {
^1da177e4 Linus Torvalds 2005-04-16 837 struct super_block *sb = inode->i_sb;
2ee20c56b Kangjie Lu 2019-03-14 838 u32 ext, ext_key, ext_bk;
^1da177e4 Linus Torvalds 2005-04-16 839 u32 last_blk, blkcnt, blk;
^1da177e4 Linus Torvalds 2005-04-16 840 u32 size;
^1da177e4 Linus Torvalds 2005-04-16 841 struct buffer_head *ext_bh;
^1da177e4 Linus Torvalds 2005-04-16 842 int i;
^1da177e4 Linus Torvalds 2005-04-16 843
08fe100d9 Geert Uytterhoeven 2015-02-17 844 pr_debug("truncate(inode=%lu, oldsize=%llu, newsize=%llu)\n",
08fe100d9 Geert Uytterhoeven 2015-02-17 845 inode->i_ino, AFFS_I(inode)->mmu_private, inode->i_size);
^1da177e4 Linus Torvalds 2005-04-16 846
^1da177e4 Linus Torvalds 2005-04-16 847 last_blk = 0;
^1da177e4 Linus Torvalds 2005-04-16 848 ext = 0;
^1da177e4 Linus Torvalds 2005-04-16 849 if (inode->i_size) {
^1da177e4 Linus Torvalds 2005-04-16 850 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
^1da177e4 Linus Torvalds 2005-04-16 851 ext = last_blk / AFFS_SB(sb)->s_hashsize;
^1da177e4 Linus Torvalds 2005-04-16 852 }
^1da177e4 Linus Torvalds 2005-04-16 853
^1da177e4 Linus Torvalds 2005-04-16 854 if (inode->i_size > AFFS_I(inode)->mmu_private) {
^1da177e4 Linus Torvalds 2005-04-16 855 struct address_space *mapping = inode->i_mapping;
^1da177e4 Linus Torvalds 2005-04-16 856 struct page *page;
f2b6a16eb Nick Piggin 2007-10-16 857 void *fsdata;
73516ace9 Fabian Frederick 2014-10-13 858 loff_t isize = inode->i_size;
^1da177e4 Linus Torvalds 2005-04-16 859 int res;
^1da177e4 Linus Torvalds 2005-04-16 860
73516ace9 Fabian Frederick 2014-10-13 861 res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, 0, &page, &fsdata);
^1da177e4 Linus Torvalds 2005-04-16 862 if (!res)
73516ace9 Fabian Frederick 2014-10-13 863 res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata);
dca3c3365 Roman Zippel 2008-04-29 864 else
dca3c3365 Roman Zippel 2008-04-29 865 inode->i_size = AFFS_I(inode)->mmu_private;
^1da177e4 Linus Torvalds 2005-04-16 866 mark_inode_dirty(inode);
^1da177e4 Linus Torvalds 2005-04-16 867 return;
^1da177e4 Linus Torvalds 2005-04-16 868 } else if (inode->i_size == AFFS_I(inode)->mmu_private)
^1da177e4 Linus Torvalds 2005-04-16 869 return;
^1da177e4 Linus Torvalds 2005-04-16 870
^1da177e4 Linus Torvalds 2005-04-16 871 // lock cache
^1da177e4 Linus Torvalds 2005-04-16 872 ext_bh = affs_get_extblock(inode, ext);
^1da177e4 Linus Torvalds 2005-04-16 873 if (IS_ERR(ext_bh)) {
1ee54b099 Fabian Frederick 2014-12-12 874 affs_warning(sb, "truncate",
1ee54b099 Fabian Frederick 2014-12-12 875 "unexpected read error for ext block %u (%ld)",
08fe100d9 Geert Uytterhoeven 2015-02-17 876 ext, PTR_ERR(ext_bh));
^1da177e4 Linus Torvalds 2005-04-16 877 return;
^1da177e4 Linus Torvalds 2005-04-16 878 }
^1da177e4 Linus Torvalds 2005-04-16 879 if (AFFS_I(inode)->i_lc) {
^1da177e4 Linus Torvalds 2005-04-16 880 /* clear linear cache */
^1da177e4 Linus Torvalds 2005-04-16 881 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
^1da177e4 Linus Torvalds 2005-04-16 882 if (AFFS_I(inode)->i_lc_size > i) {
^1da177e4 Linus Torvalds 2005-04-16 883 AFFS_I(inode)->i_lc_size = i;
^1da177e4 Linus Torvalds 2005-04-16 884 for (; i < AFFS_LC_SIZE; i++)
^1da177e4 Linus Torvalds 2005-04-16 885 AFFS_I(inode)->i_lc[i] = 0;
^1da177e4 Linus Torvalds 2005-04-16 886 }
^1da177e4 Linus Torvalds 2005-04-16 887 /* clear associative cache */
^1da177e4 Linus Torvalds 2005-04-16 888 for (i = 0; i < AFFS_AC_SIZE; i++)
^1da177e4 Linus Torvalds 2005-04-16 889 if (AFFS_I(inode)->i_ac[i].ext >= ext)
^1da177e4 Linus Torvalds 2005-04-16 890 AFFS_I(inode)->i_ac[i].ext = 0;
^1da177e4 Linus Torvalds 2005-04-16 891 }
^1da177e4 Linus Torvalds 2005-04-16 892 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
^1da177e4 Linus Torvalds 2005-04-16 893
^1da177e4 Linus Torvalds 2005-04-16 894 blkcnt = AFFS_I(inode)->i_blkcnt;
^1da177e4 Linus Torvalds 2005-04-16 895 i = 0;
^1da177e4 Linus Torvalds 2005-04-16 896 blk = last_blk;
^1da177e4 Linus Torvalds 2005-04-16 897 if (inode->i_size) {
^1da177e4 Linus Torvalds 2005-04-16 898 i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
^1da177e4 Linus Torvalds 2005-04-16 899 blk++;
^1da177e4 Linus Torvalds 2005-04-16 900 } else
^1da177e4 Linus Torvalds 2005-04-16 901 AFFS_HEAD(ext_bh)->first_data = 0;
dca3c3365 Roman Zippel 2008-04-29 902 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i);
^1da177e4 Linus Torvalds 2005-04-16 903 size = AFFS_SB(sb)->s_hashsize;
^1da177e4 Linus Torvalds 2005-04-16 904 if (size > blkcnt - blk + i)
^1da177e4 Linus Torvalds 2005-04-16 905 size = blkcnt - blk + i;
^1da177e4 Linus Torvalds 2005-04-16 906 for (; i < size; i++, blk++) {
^1da177e4 Linus Torvalds 2005-04-16 907 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
^1da177e4 Linus Torvalds 2005-04-16 908 AFFS_BLOCK(sb, ext_bh, i) = 0;
^1da177e4 Linus Torvalds 2005-04-16 909 }
^1da177e4 Linus Torvalds 2005-04-16 910 AFFS_TAIL(sb, ext_bh)->extension = 0;
^1da177e4 Linus Torvalds 2005-04-16 911 affs_fix_checksum(sb, ext_bh);
^1da177e4 Linus Torvalds 2005-04-16 912 mark_buffer_dirty_inode(ext_bh, inode);
^1da177e4 Linus Torvalds 2005-04-16 913 affs_brelse(ext_bh);
^1da177e4 Linus Torvalds 2005-04-16 914
^1da177e4 Linus Torvalds 2005-04-16 915 if (inode->i_size) {
^1da177e4 Linus Torvalds 2005-04-16 916 AFFS_I(inode)->i_blkcnt = last_blk + 1;
^1da177e4 Linus Torvalds 2005-04-16 917 AFFS_I(inode)->i_extcnt = ext + 1;
79bda4d51 Fabian Frederick 2015-04-16 918 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS)) {
^1da177e4 Linus Torvalds 2005-04-16 919 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
^1da177e4 Linus Torvalds 2005-04-16 920 u32 tmp;
0e45b67d5 Dan Carpenter 2010-08-25 921 if (IS_ERR(bh)) {
1ee54b099 Fabian Frederick 2014-12-12 922 affs_warning(sb, "truncate",
1ee54b099 Fabian Frederick 2014-12-12 923 "unexpected read error for last block %u (%ld)",
08fe100d9 Geert Uytterhoeven 2015-02-17 924 ext, PTR_ERR(bh));
^1da177e4 Linus Torvalds 2005-04-16 925 return;
^1da177e4 Linus Torvalds 2005-04-16 926 }
^1da177e4 Linus Torvalds 2005-04-16 927 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
^1da177e4 Linus Torvalds 2005-04-16 928 AFFS_DATA_HEAD(bh)->next = 0;
^1da177e4 Linus Torvalds 2005-04-16 929 affs_adjust_checksum(bh, -tmp);
^1da177e4 Linus Torvalds 2005-04-16 930 affs_brelse(bh);
^1da177e4 Linus Torvalds 2005-04-16 931 }
^1da177e4 Linus Torvalds 2005-04-16 932 } else {
^1da177e4 Linus Torvalds 2005-04-16 933 AFFS_I(inode)->i_blkcnt = 0;
^1da177e4 Linus Torvalds 2005-04-16 934 AFFS_I(inode)->i_extcnt = 1;
^1da177e4 Linus Torvalds 2005-04-16 935 }
^1da177e4 Linus Torvalds 2005-04-16 936 AFFS_I(inode)->mmu_private = inode->i_size;
^1da177e4 Linus Torvalds 2005-04-16 937 // unlock cache
^1da177e4 Linus Torvalds 2005-04-16 938
^1da177e4 Linus Torvalds 2005-04-16 939 while (ext_key) {
^1da177e4 Linus Torvalds 2005-04-16 940 ext_bh = affs_bread(sb, ext_key);
^1da177e4 Linus Torvalds 2005-04-16 941 size = AFFS_SB(sb)->s_hashsize;
^1da177e4 Linus Torvalds 2005-04-16 942 if (size > blkcnt - blk)
^1da177e4 Linus Torvalds 2005-04-16 943 size = blkcnt - blk;
2ee20c56b Kangjie Lu 2019-03-14 @944 if (ext_bh) {
2ee20c56b Kangjie Lu 2019-03-14 945 for (i = 0; i < size; i++, blk++) {
2ee20c56b Kangjie Lu 2019-03-14 946 ext_bk = AFFS_BLOCK(sb, ext_bh, i);
2ee20c56b Kangjie Lu 2019-03-14 947 affs_free_block(sb, be32_to_cpu(ext_bk));
2ee20c56b Kangjie Lu 2019-03-14 948 }
2ee20c56b Kangjie Lu 2019-03-14 949 }
^1da177e4 Linus Torvalds 2005-04-16 950 affs_free_block(sb, ext_key);
^1da177e4 Linus Torvalds 2005-04-16 @951 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
^1da177e4 Linus Torvalds 2005-04-16 952 affs_brelse(ext_bh);
^1da177e4 Linus Torvalds 2005-04-16 953 }
^1da177e4 Linus Torvalds 2005-04-16 954 affs_free_prealloc(inode);
^1da177e4 Linus Torvalds 2005-04-16 955 }
c47587955 Al Viro 2009-06-08 956
:::::: The code at line 951 was first introduced by commit
:::::: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Linux-2.6.12-rc2
:::::: TO: Linus Torvalds <torvalds@ppc970.osdl.org>
:::::: CC: Linus Torvalds <torvalds@ppc970.osdl.org>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] fs: affs: fix a NULL pointer dereference
2019-03-14 7:46 [PATCH] fs: affs: fix a NULL pointer dereference Kangjie Lu
2019-03-14 14:51 ` kbuild test robot
2019-03-19 9:00 ` Dan Carpenter
@ 2019-03-19 13:43 ` Geert Uytterhoeven
2 siblings, 0 replies; 6+ messages in thread
From: Geert Uytterhoeven @ 2019-03-19 13:43 UTC (permalink / raw)
To: Kangjie Lu
Cc: pakki001, David Sterba, Linux FS Devel, Linux Kernel Mailing List
Hi Kangjie,
On Thu, Mar 14, 2019 at 8:47 AM Kangjie Lu <kjlu@umn.edu> wrote:
> If affs_bread fails, do not use ext_bh to avoid NULL pointer
> dereference
>
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Thanks for your patch!
> --- a/fs/affs/file.c
> +++ b/fs/affs/file.c
> @@ -835,7 +835,7 @@ void
> affs_truncate(struct inode *inode)
> {
> struct super_block *sb = inode->i_sb;
> - u32 ext, ext_key;
> + u32 ext, ext_key, ext_bk;
Why adding an intermediate variable (without __be32 tag)?
> u32 last_blk, blkcnt, blk;
> u32 size;
> struct buffer_head *ext_bh;
> @@ -941,8 +941,12 @@ affs_truncate(struct inode *inode)
> size = AFFS_SB(sb)->s_hashsize;
> if (size > blkcnt - blk)
> size = blkcnt - blk;
> - for (i = 0; i < size; i++, blk++)
> - affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
> + if (ext_bh) {
> + for (i = 0; i < size; i++, blk++) {
> + ext_bk = AFFS_BLOCK(sb, ext_bh, i);
> + affs_free_block(sb, be32_to_cpu(ext_bk));
> + }
Now this ignores all errors, silently.
What about handling actual errors, and propagating them up?
> + }
> affs_free_block(sb, ext_key);
> ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
> affs_brelse(ext_bh);
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] fs: affs: fix a NULL pointer dereference
2019-03-15 7:42 Kangjie Lu
@ 2019-03-21 14:45 ` David Sterba
0 siblings, 0 replies; 6+ messages in thread
From: David Sterba @ 2019-03-21 14:45 UTC (permalink / raw)
To: Kangjie Lu; +Cc: pakki001, linux-fsdevel, linux-kernel
On Fri, Mar 15, 2019 at 02:42:44AM -0500, Kangjie Lu wrote:
> If affs_bread fails, do not use ext_bh to avoid NULL pointer
> dereference
>
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Tanks for the patch. I'll need some more time to get familiar with the
AFFS code to review your patch.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] fs: affs: fix a NULL pointer dereference
@ 2019-03-15 7:42 Kangjie Lu
2019-03-21 14:45 ` David Sterba
0 siblings, 1 reply; 6+ messages in thread
From: Kangjie Lu @ 2019-03-15 7:42 UTC (permalink / raw)
To: kjlu; +Cc: pakki001, David Sterba, linux-fsdevel, linux-kernel
If affs_bread fails, do not use ext_bh to avoid NULL pointer
dereference
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
---
fs/affs/file.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/affs/file.c b/fs/affs/file.c
index a85817f54483..29cbc8eda085 100644
--- a/fs/affs/file.c
+++ b/fs/affs/file.c
@@ -941,8 +941,10 @@ affs_truncate(struct inode *inode)
size = AFFS_SB(sb)->s_hashsize;
if (size > blkcnt - blk)
size = blkcnt - blk;
- for (i = 0; i < size; i++, blk++)
- affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
+ if (ext_bh) {
+ for (i = 0; i < size; i++, blk++)
+ affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
+ }
affs_free_block(sb, ext_key);
ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
affs_brelse(ext_bh);
--
2.17.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-03-21 14:44 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-03-14 7:46 [PATCH] fs: affs: fix a NULL pointer dereference Kangjie Lu
2019-03-14 14:51 ` kbuild test robot
2019-03-19 9:00 ` Dan Carpenter
2019-03-19 13:43 ` Geert Uytterhoeven
2019-03-15 7:42 Kangjie Lu
2019-03-21 14:45 ` David Sterba
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