fs/ntfs3: Validate data run offset

This adds sanity checks for data run offset. We should make sure data
run offset is legit before trying to unpack them, otherwise we may
encounter use-after-free or some unexpected memory access behaviors.

[   82.940342] BUG: KASAN: use-after-free in run_unpack+0x2e3/0x570
[   82.941180] Read of size 1 at addr ffff888008a8487f by task mount/240
[   82.941670]
[   82.942069] CPU: 0 PID: 240 Comm: mount Not tainted 5.19.0+ torvalds#15
[   82.942482] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[   82.943720] Call Trace:
[   82.944204]  <TASK>
[   82.944471]  dump_stack_lvl+0x49/0x63
[   82.944908]  print_report.cold+0xf5/0x67b
[   82.945141]  ? __wait_on_bit+0x106/0x120
[   82.945750]  ? run_unpack+0x2e3/0x570
[   82.946626]  kasan_report+0xa7/0x120
[   82.947046]  ? run_unpack+0x2e3/0x570
[   82.947280]  __asan_load1+0x51/0x60
[   82.947483]  run_unpack+0x2e3/0x570
[   82.947709]  ? memcpy+0x4e/0x70
[   82.947927]  ? run_pack+0x7a0/0x7a0
[   82.948158]  run_unpack_ex+0xad/0x3f0
[   82.948399]  ? mi_enum_attr+0x14a/0x200
[   82.948717]  ? run_unpack+0x570/0x570
[   82.949072]  ? ni_enum_attr_ex+0x1b2/0x1c0
[   82.949332]  ? ni_fname_type.part.0+0xd0/0xd0
[   82.949611]  ? mi_read+0x262/0x2c0
[   82.949970]  ? ntfs_cmp_names_cpu+0x125/0x180
[   82.950249]  ntfs_iget5+0x632/0x1870
[   82.950621]  ? ntfs_get_block_bmap+0x70/0x70
[   82.951192]  ? evict+0x223/0x280
[   82.951525]  ? iput.part.0+0x286/0x320
[   82.951969]  ntfs_fill_super+0x1321/0x1e20
[   82.952436]  ? put_ntfs+0x1d0/0x1d0
[   82.952822]  ? vsprintf+0x20/0x20
[   82.953188]  ? mutex_unlock+0x81/0xd0
[   82.953379]  ? set_blocksize+0x95/0x150
[   82.954001]  get_tree_bdev+0x232/0x370
[   82.954438]  ? put_ntfs+0x1d0/0x1d0
[   82.954700]  ntfs_fs_get_tree+0x15/0x20
[   82.955049]  vfs_get_tree+0x4c/0x130
[   82.955292]  path_mount+0x645/0xfd0
[   82.955615]  ? putname+0x80/0xa0
[   82.955955]  ? finish_automount+0x2e0/0x2e0
[   82.956310]  ? kmem_cache_free+0x110/0x390
[   82.956723]  ? putname+0x80/0xa0
[   82.957023]  do_mount+0xd6/0xf0
[   82.957411]  ? path_mount+0xfd0/0xfd0
[   82.957638]  ? __kasan_check_write+0x14/0x20
[   82.957948]  __x64_sys_mount+0xca/0x110
[   82.958310]  do_syscall_64+0x3b/0x90
[   82.958719]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[   82.959341] RIP: 0033:0x7fd0d1ce948a
[   82.960193] Code: 48 8b 0d 11 fa 2a 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 008
[   82.961532] RSP: 002b:00007ffe59ff69a8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
[   82.962527] RAX: ffffffffffffffda RBX: 0000564dcc107060 RCX: 00007fd0d1ce948a
[   82.963266] RDX: 0000564dcc107260 RSI: 0000564dcc1072e0 RDI: 0000564dcc10fce0
[   82.963686] RBP: 0000000000000000 R08: 0000564dcc107280 R09: 0000000000000020
[   82.964272] R10: 00000000c0ed0000 R11: 0000000000000202 R12: 0000564dcc10fce0
[   82.964785] R13: 0000564dcc107260 R14: 0000000000000000 R15: 00000000ffffffff

Signed-off-by: Edward Lo <[email protected]>
Signed-off-by: Konstantin Komarov <[email protected]>

Author: Elden-Ring

fs/ntfs3/attrib.c

@@ -101,6 +101,10 @@ static int attr_load_runs(struct ATTRIB *attr, struct ntfs_inode *ni,
 
 	asize = le32_to_cpu(attr->size);
 	run_off = le16_to_cpu(attr->nres.run_off);
+
+	if (run_off > asize)
+		return -EINVAL;
+
 	err = run_unpack_ex(run, ni->mi.sbi, ni->mi.rno, svcn, evcn,
 			    vcn ? *vcn : svcn, Add2Ptr(attr, run_off),
 			    asize - run_off);
@@ -1232,6 +1236,10 @@ int attr_load_runs_vcn(struct ntfs_inode *ni, enum ATTR_TYPE type,
 	}
 
 	ro = le16_to_cpu(attr->nres.run_off);
+
+	if (ro > le32_to_cpu(attr->size))
+		return -EINVAL;
+
 	err = run_unpack_ex(run, ni->mi.sbi, ni->mi.rno, svcn, evcn, svcn,
 			    Add2Ptr(attr, ro), le32_to_cpu(attr->size) - ro);
 	if (err < 0)
@@ -1901,6 +1909,11 @@ int attr_collapse_range(struct ntfs_inode *ni, u64 vbo, u64 bytes)
 			u16 le_sz;
 			u16 roff = le16_to_cpu(attr->nres.run_off);
 
+			if (roff > le32_to_cpu(attr->size)) {
+				err = -EINVAL;
+				goto out;
+			}
+
 			run_unpack_ex(RUN_DEALLOCATE, sbi, ni->mi.rno, svcn,
 				      evcn1 - 1, svcn, Add2Ptr(attr, roff),
 				      le32_to_cpu(attr->size) - roff);

fs/ntfs3/attrlist.c

@@ -68,6 +68,11 @@ int ntfs_load_attr_list(struct ntfs_inode *ni, struct ATTRIB *attr)
 
 		run_init(&ni->attr_list.run);
 
+		if (run_off > le32_to_cpu(attr->size)) {
+			err = -EINVAL;
+			goto out;
+		}
+
 		err = run_unpack_ex(&ni->attr_list.run, ni->mi.sbi, ni->mi.rno,
 				    0, le64_to_cpu(attr->nres.evcn), 0,
 				    Add2Ptr(attr, run_off),

fs/ntfs3/frecord.c

@@ -568,6 +568,12 @@ static int ni_repack(struct ntfs_inode *ni)
 		}
 
 		roff = le16_to_cpu(attr->nres.run_off);
+
+		if (roff > le32_to_cpu(attr->size)) {
+			err = -EINVAL;
+			break;
+		}
+
 		err = run_unpack(&run, sbi, ni->mi.rno, svcn, evcn, svcn,
 				 Add2Ptr(attr, roff),
 				 le32_to_cpu(attr->size) - roff);
@@ -1589,6 +1595,9 @@ int ni_delete_all(struct ntfs_inode *ni)
 		asize = le32_to_cpu(attr->size);
 		roff = le16_to_cpu(attr->nres.run_off);
 
+		if (roff > asize)
+			return -EINVAL;
+
 		/* run==1 means unpack and deallocate. */
 		run_unpack_ex(RUN_DEALLOCATE, sbi, ni->mi.rno, svcn, evcn, svcn,
 			      Add2Ptr(attr, roff), asize - roff);
@@ -2291,6 +2300,11 @@ int ni_decompress_file(struct ntfs_inode *ni)
 		asize = le32_to_cpu(attr->size);
 		roff = le16_to_cpu(attr->nres.run_off);
 
+		if (roff > asize) {
+			err = -EINVAL;
+			goto out;
+		}
+
 		/*run==1  Means unpack and deallocate. */
 		run_unpack_ex(RUN_DEALLOCATE, sbi, ni->mi.rno, svcn, evcn, svcn,
 			      Add2Ptr(attr, roff), asize - roff);

fs/ntfs3/fslog.c

@@ -2727,6 +2727,9 @@ static inline bool check_attr(const struct MFT_REC *rec,
 			return false;
 		}
 
+		if (run_off > asize)
+			return false;
+
 		if (run_unpack(NULL, sbi, 0, svcn, evcn, svcn,
 			       Add2Ptr(attr, run_off), asize - run_off) < 0) {
 			return false;
@@ -4769,6 +4772,12 @@ int log_replay(struct ntfs_inode *ni, bool *initialized)
 		u16 roff = le16_to_cpu(attr->nres.run_off);
 		CLST svcn = le64_to_cpu(attr->nres.svcn);
 
+		if (roff > t32) {
+			kfree(oa->attr);
+			oa->attr = NULL;
+			goto fake_attr;
+		}
+
 		err = run_unpack(&oa->run0, sbi, inode->i_ino, svcn,
 				 le64_to_cpu(attr->nres.evcn), svcn,
 				 Add2Ptr(attr, roff), t32 - roff);

fs/ntfs3/inode.c

@@ -364,6 +364,11 @@ static struct inode *ntfs_read_mft(struct inode *inode,
 attr_unpack_run:
 	roff = le16_to_cpu(attr->nres.run_off);
 
+	if (roff > asize) {
+		err = -EINVAL;
+		goto out;
+	}
+
 	t64 = le64_to_cpu(attr->nres.svcn);
 	err = run_unpack_ex(run, sbi, ino, t64, le64_to_cpu(attr->nres.evcn),
 			    t64, Add2Ptr(attr, roff), asize - roff);