From: Leon Romanovsky <leonro@xxxxxxxxxx>
Partially revert the commit mentioned in the Fixes line to make sure
that allocation and erasing multicast struct are locked.
==================================================================
BUG: KASAN: use-after-free in ucma_cleanup_multicast drivers/infiniband/core/ucma.c:491 [inline]
BUG: KASAN: use-after-free in ucma_destroy_private_ctx+0x914/0xb70 drivers/infiniband/core/ucma.c:579
Read of size 8 at addr ffff88801bb74b00 by task syz-executor.1/25529
CPU: 0 PID: 25529 Comm: syz-executor.1 Not tainted 5.16.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247
__kasan_report mm/kasan/report.c:433 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:450
ucma_cleanup_multicast drivers/infiniband/core/ucma.c:491 [inline]
ucma_destroy_private_ctx+0x914/0xb70 drivers/infiniband/core/ucma.c:579
ucma_destroy_id+0x1e6/0x280 drivers/infiniband/core/ucma.c:614
ucma_write+0x25c/0x350 drivers/infiniband/core/ucma.c:1732
vfs_write+0x28e/0xae0 fs/read_write.c:588
ksys_write+0x1ee/0x250 fs/read_write.c:643
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f2fcd207e99
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b
4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2fcbb7d168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f2fcd31af60 RCX: 00007f2fcd207e99
RDX: 0000000000000018 RSI: 00000000200000c0 RDI: 0000000000000004
RBP: 00007f2fcd261ff1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff66a135bf R14: 00007f2fcbb7d300 R15: 0000000000022000
</TASK>
Fixes: 95fe51096b7a ("RDMA/ucma: Remove mc_list and rely on xarray")
Reported-by: syzbot+e3f96c43d19782dd14a7@xxxxxxxxxxxxxxxxxxxxxxxxx
Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Reviewed-by: Maor Gottlieb <maorg@xxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
---
drivers/infiniband/core/ucma.c | 34 +++++++++++++++++++++++-----------
1 file changed, 23 insertions(+), 11 deletions(-)
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index 2b72c4fa9550..9d6ac9dff39a 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -95,6 +95,7 @@ struct ucma_context {
u64 uid;
struct list_head list;
+ struct list_head mc_list;
struct work_struct close_work;
};
@@ -105,6 +106,7 @@ struct ucma_multicast {
u64 uid;
u8 join_state;
+ struct list_head list;
struct sockaddr_storage addr;
};
@@ -198,6 +200,7 @@ static struct ucma_context *ucma_alloc_ctx(struct ucma_file *file)
INIT_WORK(&ctx->close_work, ucma_close_id);
init_completion(&ctx->comp);
+ INIT_LIST_HEAD(&ctx->mc_list);
/* So list_del() will work if we don't do ucma_finish_ctx() */
INIT_LIST_HEAD(&ctx->list);
ctx->file = file;
@@ -484,19 +487,19 @@ static ssize_t ucma_create_id(struct ucma_file *file, const char __user *inbuf,
static void ucma_cleanup_multicast(struct ucma_context *ctx)
{
- struct ucma_multicast *mc;
- unsigned long index;
+ struct ucma_multicast *mc, *tmp;
- xa_for_each(&multicast_table, index, mc) {
- if (mc->ctx != ctx)
- continue;
+ xa_lock(&multicast_table);
+ list_for_each_entry_safe(mc, tmp, &ctx->mc_list, list) {
+ list_del(&mc->list);
/*
* At this point mc->ctx->ref is 0 so the mc cannot leave the
* lock on the reader and this is enough serialization
*/
- xa_erase(&multicast_table, index);
+ __xa_erase(&multicast_table, mc->id);
kfree(mc);
}
+ xa_unlock(&multicast_table);
}
static void ucma_cleanup_mc_events(struct ucma_multicast *mc)
@@ -1469,12 +1472,16 @@ static ssize_t ucma_process_join(struct ucma_file *file,
mc->uid = cmd->uid;
memcpy(&mc->addr, addr, cmd->addr_size);
- if (xa_alloc(&multicast_table, &mc->id, NULL, xa_limit_32b,
+ xa_lock(&multicast_table);
+ if (__xa_alloc(&multicast_table, &mc->id, NULL, xa_limit_32b,
GFP_KERNEL)) {
ret = -ENOMEM;
goto err_free_mc;
}
+ list_add_tail(&mc->list, &ctx->mc_list);
+ xa_unlock(&multicast_table);
+
mutex_lock(&ctx->mutex);
ret = rdma_join_multicast(ctx->cm_id, (struct sockaddr *)&mc->addr,
join_state, mc);
@@ -1500,8 +1507,11 @@ static ssize_t ucma_process_join(struct ucma_file *file,
mutex_unlock(&ctx->mutex);
ucma_cleanup_mc_events(mc);
err_xa_erase:
- xa_erase(&multicast_table, mc->id);
+ xa_lock(&multicast_table);
+ list_del(&mc->list);
+ __xa_erase(&multicast_table, mc->id);
err_free_mc:
+ xa_unlock(&multicast_table);
kfree(mc);
err_put_ctx:
ucma_put_ctx(ctx);
@@ -1569,15 +1579,17 @@ static ssize_t ucma_leave_multicast(struct ucma_file *file,
mc = ERR_PTR(-EINVAL);
else if (!refcount_inc_not_zero(&mc->ctx->ref))
mc = ERR_PTR(-ENXIO);
- else
- __xa_erase(&multicast_table, mc->id);
- xa_unlock(&multicast_table);
if (IS_ERR(mc)) {
+ xa_unlock(&multicast_table);
ret = PTR_ERR(mc);
goto out;
}
+ list_del(&mc->list);
+ __xa_erase(&multicast_table, mc->id);
+ xa_unlock(&multicast_table);
+
mutex_lock(&mc->ctx->mutex);
rdma_leave_multicast(mc->ctx->cm_id, (struct sockaddr *) &mc->addr);
mutex_unlock(&mc->ctx->mutex);
--
2.34.1
