In the Linux kernel, the following vulnerability has been resolved:
mmc: sdio: fix possible resource leaks in some error paths
If sdio_add_func() or sdio_init_func() fails, sdio_remove_func() can
not release the resources, because the sdio function is not presented
in these two cases, it won’t call of_node_put() or put_device().
To fix these leaks, make sdio_func_present() only control whether
device_del() needs to be called or not, then always call of_node_put()
and put_device().
In error case in sdio_init_func(), the reference of ‘card->dev’ is
not get, to avoid redundant put in sdio_free_func_cis(), move the
get_device() to sdio_alloc_func() and put_device() to sdio_release_func(),
it can keep the get/put function be balanced.
Without this patch, while doing fault inject test, it can get the
following leak reports, after this fix, the leak is gone.
unreferenced object 0xffff888112514000 (size 2048):
comm “kworker/3:2”, pid 65, jiffies 4294741614 (age 124.774s)
hex dump (first 32 bytes):
00 e0 6f 12 81 88 ff ff 60 58 8d 06 81 88 ff ff …o…`X…
10 40 51 12 81 88 ff ff 10 40 51 12 81 88 ff ff .@Q…@Q…
backtrace:
[<000000009e5931da>] kmalloc_trace+0x21/0x110
[<000000002f839ccb>] mmc_alloc_card+0x38/0xb0 [mmc_core]
[<0000000004adcbf6>] mmc_sdio_init_card+0xde/0x170 [mmc_core]
[<000000007538fea0>] mmc_attach_sdio+0xcb/0x1b0 [mmc_core]
[<00000000d4fdeba7>] mmc_rescan+0x54a/0x640 [mmc_core]
unreferenced object 0xffff888112511000 (size 2048):
comm “kworker/3:2”, pid 65, jiffies 4294741623 (age 124.766s)
hex dump (first 32 bytes):
00 40 51 12 81 88 ff ff e0 58 8d 06 81 88 ff ff .@Q…X…
10 10 51 12 81 88 ff ff 10 10 51 12 81 88 ff ff …Q…Q…
backtrace:
[<000000009e5931da>] kmalloc_trace+0x21/0x110
[<00000000fcbe706c>] sdio_alloc_func+0x35/0x100 [mmc_core]
[<00000000c68f4b50>] mmc_attach_sdio.cold.18+0xb1/0x395 [mmc_core]
[<00000000d4fdeba7>] mmc_rescan+0x54a/0x640 [mmc_core]
git.kernel.org/stable/c/1e06cf04239e202248c8fa356bf11449dc73cfbd
git.kernel.org/stable/c/30716d9f0fa1766e522cf24c8a456244e4fc9931
git.kernel.org/stable/c/5c7858adada31dbed042448cff6997dd6efc472a
git.kernel.org/stable/c/605d9fb9556f8f5fb4566f4df1480f280f308ded
git.kernel.org/stable/c/761db46b29b496946046d8cb33c7ea6de6bef36e
git.kernel.org/stable/c/92ff03c2563c9b57a027c744750f3b7d2f261c58
git.kernel.org/stable/c/f855d31bb38d663c3ba672345d7cce9324ba3b72