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authorBob Copeland <me@bobcopeland.com>2008-08-15 03:40:47 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-08-15 11:35:44 -0400
commit9419fc1c957d600093baaea247fef23cca3b4e93 (patch)
tree532606ac97d86d8952ffcdd8f8513b1499c10bf8 /fs/omfs
parentc963343a1150106819773e828c9b237ed977615b (diff)
omfs: fix oops when file metadata is corrupted
A fuzzed fileystem image failed with OMFS when the extent count was used in a loop without being checked against the max number of extents. It also provoked a signed division for an array index that was checked as if unsigned, leading to index by -1. omfsck will be updated to fix these cases, in the meantime bail out gracefully. Reported-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Bob Copeland <me@bobcopeland.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/omfs')
-rw-r--r--fs/omfs/bitmap.c5
-rw-r--r--fs/omfs/file.c33
2 files changed, 29 insertions, 9 deletions
diff --git a/fs/omfs/bitmap.c b/fs/omfs/bitmap.c
index 697663b01bae..e1c0ec0ae989 100644
--- a/fs/omfs/bitmap.c
+++ b/fs/omfs/bitmap.c
@@ -92,7 +92,7 @@ int omfs_allocate_block(struct super_block *sb, u64 block)
92 struct buffer_head *bh; 92 struct buffer_head *bh;
93 struct omfs_sb_info *sbi = OMFS_SB(sb); 93 struct omfs_sb_info *sbi = OMFS_SB(sb);
94 int bits_per_entry = 8 * sb->s_blocksize; 94 int bits_per_entry = 8 * sb->s_blocksize;
95 int map, bit; 95 unsigned int map, bit;
96 int ret = 0; 96 int ret = 0;
97 u64 tmp; 97 u64 tmp;
98 98
@@ -176,7 +176,8 @@ int omfs_clear_range(struct super_block *sb, u64 block, int count)
176 struct omfs_sb_info *sbi = OMFS_SB(sb); 176 struct omfs_sb_info *sbi = OMFS_SB(sb);
177 int bits_per_entry = 8 * sb->s_blocksize; 177 int bits_per_entry = 8 * sb->s_blocksize;
178 u64 tmp; 178 u64 tmp;
179 int map, bit, ret; 179 unsigned int map, bit;
180 int ret;
180 181
181 tmp = block; 182 tmp = block;
182 bit = do_div(tmp, bits_per_entry); 183 bit = do_div(tmp, bits_per_entry);
diff --git a/fs/omfs/file.c b/fs/omfs/file.c
index 7e2499053e4d..834b2331f6b3 100644
--- a/fs/omfs/file.c
+++ b/fs/omfs/file.c
@@ -26,6 +26,13 @@ static int omfs_sync_file(struct file *file, struct dentry *dentry,
26 return err ? -EIO : 0; 26 return err ? -EIO : 0;
27} 27}
28 28
29static u32 omfs_max_extents(struct omfs_sb_info *sbi, int offset)
30{
31 return (sbi->s_sys_blocksize - offset -
32 sizeof(struct omfs_extent)) /
33 sizeof(struct omfs_extent_entry) + 1;
34}
35
29void omfs_make_empty_table(struct buffer_head *bh, int offset) 36void omfs_make_empty_table(struct buffer_head *bh, int offset)
30{ 37{
31 struct omfs_extent *oe = (struct omfs_extent *) &bh->b_data[offset]; 38 struct omfs_extent *oe = (struct omfs_extent *) &bh->b_data[offset];
@@ -45,6 +52,7 @@ int omfs_shrink_inode(struct inode *inode)
45 struct buffer_head *bh; 52 struct buffer_head *bh;
46 u64 next, last; 53 u64 next, last;
47 u32 extent_count; 54 u32 extent_count;
55 u32 max_extents;
48 int ret; 56 int ret;
49 57
50 /* traverse extent table, freeing each entry that is greater 58 /* traverse extent table, freeing each entry that is greater
@@ -62,15 +70,18 @@ int omfs_shrink_inode(struct inode *inode)
62 goto out; 70 goto out;
63 71
64 oe = (struct omfs_extent *)(&bh->b_data[OMFS_EXTENT_START]); 72 oe = (struct omfs_extent *)(&bh->b_data[OMFS_EXTENT_START]);
73 max_extents = omfs_max_extents(sbi, OMFS_EXTENT_START);
65 74
66 for (;;) { 75 for (;;) {
67 76
68 if (omfs_is_bad(sbi, (struct omfs_header *) bh->b_data, next)) { 77 if (omfs_is_bad(sbi, (struct omfs_header *) bh->b_data, next))
69 brelse(bh); 78 goto out_brelse;
70 goto out;
71 }
72 79
73 extent_count = be32_to_cpu(oe->e_extent_count); 80 extent_count = be32_to_cpu(oe->e_extent_count);
81
82 if (extent_count > max_extents)
83 goto out_brelse;
84
74 last = next; 85 last = next;
75 next = be64_to_cpu(oe->e_next); 86 next = be64_to_cpu(oe->e_next);
76 entry = &oe->e_entry; 87 entry = &oe->e_entry;
@@ -98,10 +109,14 @@ int omfs_shrink_inode(struct inode *inode)
98 if (!bh) 109 if (!bh)
99 goto out; 110 goto out;
100 oe = (struct omfs_extent *) (&bh->b_data[OMFS_EXTENT_CONT]); 111 oe = (struct omfs_extent *) (&bh->b_data[OMFS_EXTENT_CONT]);
112 max_extents = omfs_max_extents(sbi, OMFS_EXTENT_CONT);
101 } 113 }
102 ret = 0; 114 ret = 0;
103out: 115out:
104 return ret; 116 return ret;
117out_brelse:
118 brelse(bh);
119 return ret;
105} 120}
106 121
107static void omfs_truncate(struct inode *inode) 122static void omfs_truncate(struct inode *inode)
@@ -154,9 +169,7 @@ static int omfs_grow_extent(struct inode *inode, struct omfs_extent *oe,
154 goto out; 169 goto out;
155 } 170 }
156 } 171 }
157 max_count = (sbi->s_sys_blocksize - OMFS_EXTENT_START - 172 max_count = omfs_max_extents(sbi, OMFS_EXTENT_START);
158 sizeof(struct omfs_extent)) /
159 sizeof(struct omfs_extent_entry) + 1;
160 173
161 /* TODO: add a continuation block here */ 174 /* TODO: add a continuation block here */
162 if (be32_to_cpu(oe->e_extent_count) > max_count-1) 175 if (be32_to_cpu(oe->e_extent_count) > max_count-1)
@@ -225,6 +238,7 @@ static int omfs_get_block(struct inode *inode, sector_t block,
225 sector_t next, offset; 238 sector_t next, offset;
226 int ret; 239 int ret;
227 u64 new_block; 240 u64 new_block;
241 u32 max_extents;
228 int extent_count; 242 int extent_count;
229 struct omfs_extent *oe; 243 struct omfs_extent *oe;
230 struct omfs_extent_entry *entry; 244 struct omfs_extent_entry *entry;
@@ -238,6 +252,7 @@ static int omfs_get_block(struct inode *inode, sector_t block,
238 goto out; 252 goto out;
239 253
240 oe = (struct omfs_extent *)(&bh->b_data[OMFS_EXTENT_START]); 254 oe = (struct omfs_extent *)(&bh->b_data[OMFS_EXTENT_START]);
255 max_extents = omfs_max_extents(sbi, OMFS_EXTENT_START);
241 next = inode->i_ino; 256 next = inode->i_ino;
242 257
243 for (;;) { 258 for (;;) {
@@ -249,6 +264,9 @@ static int omfs_get_block(struct inode *inode, sector_t block,
249 next = be64_to_cpu(oe->e_next); 264 next = be64_to_cpu(oe->e_next);
250 entry = &oe->e_entry; 265 entry = &oe->e_entry;
251 266
267 if (extent_count > max_extents)
268 goto out_brelse;
269
252 offset = find_block(inode, entry, block, extent_count, &remain); 270 offset = find_block(inode, entry, block, extent_count, &remain);
253 if (offset > 0) { 271 if (offset > 0) {
254 ret = 0; 272 ret = 0;
@@ -266,6 +284,7 @@ static int omfs_get_block(struct inode *inode, sector_t block,
266 if (!bh) 284 if (!bh)
267 goto out; 285 goto out;
268 oe = (struct omfs_extent *) (&bh->b_data[OMFS_EXTENT_CONT]); 286 oe = (struct omfs_extent *) (&bh->b_data[OMFS_EXTENT_CONT]);
287 max_extents = omfs_max_extents(sbi, OMFS_EXTENT_CONT);
269 } 288 }
270 if (create) { 289 if (create) {
271 ret = omfs_grow_extent(inode, oe, &new_block); 290 ret = omfs_grow_extent(inode, oe, &new_block);