This is a note to let you know that I've just added the patch titled net: farsync: Fix kmemleak when rmmods farsync to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-farsync-fix-kmemleak-when-rmmods-farsync.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit efa4aada1f602e150243581ba23e1e5254cd37b0 Author: Li Zetao <lizetao1@xxxxxxxxxx> Date: Thu Dec 8 20:05:40 2022 +0800 net: farsync: Fix kmemleak when rmmods farsync [ Upstream commit 2f623aaf9f31de968dea6169849706a2f9be444c ] There are two memory leaks reported by kmemleak: unreferenced object 0xffff888114b20200 (size 128): comm "modprobe", pid 4846, jiffies 4295146524 (age 401.345s) hex dump (first 32 bytes): e0 62 57 09 81 88 ff ff e0 62 57 09 81 88 ff ff .bW......bW..... 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff815bcd82>] kmalloc_trace+0x22/0x60 [<ffffffff83d35c78>] __hw_addr_add_ex+0x198/0x6c0 [<ffffffff83d3989d>] dev_addr_init+0x13d/0x230 [<ffffffff83d1063d>] alloc_netdev_mqs+0x10d/0xe50 [<ffffffff82b4a06e>] alloc_hdlcdev+0x2e/0x80 [<ffffffffa016a741>] fst_add_one+0x601/0x10e0 [farsync] ... unreferenced object 0xffff88810b85b000 (size 1024): comm "modprobe", pid 4846, jiffies 4295146523 (age 401.346s) hex dump (first 32 bytes): 00 00 b0 02 00 c9 ff ff 00 70 0a 00 00 c9 ff ff .........p...... 00 00 00 f2 00 00 00 f3 0a 00 00 00 02 00 00 00 ................ backtrace: [<ffffffff815bcd82>] kmalloc_trace+0x22/0x60 [<ffffffffa016a294>] fst_add_one+0x154/0x10e0 [farsync] [<ffffffff82060e83>] local_pci_probe+0xd3/0x170 ... The root cause is traced to the netdev and fst_card_info are not freed when removes one fst in fst_remove_one(), which may trigger oom if repeated insmod and rmmod module. Fix it by adding free_netdev() and kfree() in fst_remove_one(), just as the operations on the error handling path in fst_add_one(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Li Zetao <lizetao1@xxxxxxxxxx> Reviewed-by: Jiri Pirko <jiri@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/wan/farsync.c b/drivers/net/wan/farsync.c index 2a3f0f1a2b0a..bc249f81c80d 100644 --- a/drivers/net/wan/farsync.c +++ b/drivers/net/wan/farsync.c @@ -2617,6 +2617,7 @@ fst_remove_one(struct pci_dev *pdev) for (i = 0; i < card->nports; i++) { struct net_device *dev = port_to_dev(&card->ports[i]); unregister_hdlc_device(dev); + free_netdev(dev); } fst_disable_intr(card); @@ -2637,6 +2638,7 @@ fst_remove_one(struct pci_dev *pdev) card->tx_dma_handle_card); } fst_card_array[card->card_no] = NULL; + kfree(card); } static struct pci_driver fst_driver = {