[PATCH AUTOSEL 5.15 03/22] fs/ntfs3: Validate data run offset

Sasha Levin
2022-12-27T20:34:38Z

[ Upstream commit 6db620863f8528ed9a9aa5ad323b26554a17881d ]

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+ #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 <edward.lo@ambergroup.io>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ntfs3/attrib.c | 13 +++++++++++++
fs/ntfs3/attrlist.c | 5 +++++
fs/ntfs3/frecord.c | 14 ++++++++++++++
fs/ntfs3/fslog.c | 9 +++++++++
fs/ntfs3/inode.c | 5 +++++
5 files changed, 46 insertions(+)

diff --git a/fs/ntfs3/attrib.c b/fs/ntfs3/attrib.c
index e8c00dda42ad..43e85c493c05 100644
--- a/fs/ntfs3/attrib.c
+++ b/fs/ntfs3/attrib.c
@@ -101,6 +101,10 @@ 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);
@@ -1157,6 +1161,10 @@ 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)
@@ -1832,6 +1840,11 @@ 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);
diff --git a/fs/ntfs3/attrlist.c b/fs/ntfs3/attrlist.c
index bad6d8a849a2..c0c6bcbc8c05 100644
--- a/fs/ntfs3/attrlist.c
+++ b/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),
diff --git a/fs/ntfs3/frecord.c b/fs/ntfs3/frecord.c
index 18842998c8fa..cdeb0b51f0ba 100644
--- a/fs/ntfs3/frecord.c
+++ b/fs/ntfs3/frecord.c
@@ -567,6 +567,12 @@ 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);
@@ -1541,6 +1547,9 @@ 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);
@@ -2242,6 +2251,11 @@ 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);
diff --git a/fs/ntfs3/fslog.c b/fs/ntfs3/fslog.c
index 614513460b8e..bcdddcd7bc79 100644
--- a/fs/ntfs3/fslog.c
+++ b/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);
diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c
index 64b4a3c29878..83d4c9f42d9c 100644
--- a/fs/ntfs3/inode.c
+++ b/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);
--
2.35.1