medium CVSS 5.5

CVE-2023-52730·Kernel vulnerability

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]

Severity
medium
Software
Kernel
Fixed in
6.1.13
Published
2024-05-21

Affected versions

From: 5.16

Until: 6.1.13

Fixed in: 6.1.13

How to fix this CVE

Update your Linux kernel to version 6.1.13 or later to patch a resource leak vulnerability in the SDIO subsystem. This vulnerability can cause memory leaks when SDIO function initialization or addition fails during device enumeration. Apply this update as part of your regular kernel maintenance cycle to prevent gradual memory exhaustion on systems with SD card readers or other SDIO devices.

sudo dnf update kernel kernel-headers kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Check your kernel version: uname -r (vulnerable if output shows 5.16 through 6.1.12)
  2. Verify SDIO devices are present: lsmod | grep sdio (look for mmc_core, mmc_sdio_ops loaded)
  3. Check kernel logs for SDIO initialization errors: sudo dmesg | grep -i 'sdio\|mmc' (look for device_add or func_init failures)
  4. After patching, verify fix: uname -r should show 6.1.13 or higher, and no memory leak warnings should appear in dmesg during SD card enumeration

FAQ

What is CVE-2023-52730?

This vulnerability describes a resource leak in the Linux kernel's SDIO (Secure Digital I/O) subsystem where dynamically allocated device structures and reference counts are not properly freed when SDIO function initialization or registration fails, causing memory exhaustion over time.

Is CVE-2023-52730 being actively exploited?

No, this vulnerability is not listed in CISA's Known Exploited Vulnerabilities catalog and has no public exploits available. It requires physical or internal access to trigger SDIO device failures.

What versions of Kernel are affected by CVE-2023-52730?

Linux kernel versions 5.16 through 6.1.12 are vulnerable; version 6.1.13 and later contain the fix.

How do I check if my server is vulnerable to CVE-2023-52730?

Run 'uname -r' and compare the output against the affected range 5.16–6.1.12. If your version falls in this range and you have SDIO devices (check 'lsmod | grep mmc'), your system is vulnerable.

Does Defensia detect CVE-2023-52730?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If the Linux kernel is installed on a monitored server, CVE-2023-52730 will appear in your dashboard with remediation steps.

Related Kernel CVEs

CVE-2026-64033CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: RDMA/rtrs: Fix use-after-free in path file creation cleanup In the error path of rtrs_srv_create_path_files(), the sysfs root folders may already have been created and srv_path->kobj may already have been initialized. If a later step fails, the cleanup currently calls kobject_put(&srv_path->kobj) before rtrs_srv_destroy_once_sysfs_root_folders(srv_path). kobject_put() may drop the last reference to srv_path->kobj and invoke the release callback, rtrs_srv_release(), which frees srv_path. The following call to rtrs_srv_destroy_once_sysfs_root_folders(srv_path) then dereferences srv_path internally to access srv_path->srv, resulting in a use-after-free. This failure path is reached before rtrs_srv_create_path_files() returns success, so the successful-path lifetime handling is not involved. Fix this by destroying the sysfs root folders before calling kobject_put(&srv_path->kobj), so srv_path is still valid while the helper accesses it. This issue was found by a static analysis tool I am developing.
CVE-2026-64037CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: mld: fix TSO segmentation explosion when AMSDU is disabled When the TLC notification disables AMSDU for a TID, the MLD driver sets max_tid_amsdu_len to the sentinel value 1. The TSO segmentation path in iwl_mld_tx_tso_segment() checks for zero but not for this sentinel, allowing it to reach the num_subframes calculation: num_subframes = (max_tid_amsdu_len + pad) / (subf_len + pad) = (1 + 2) / (1534 + 2) = 0 This zero propagates to iwl_tx_tso_segment() which sets: gso_size = num_subframes * mss = 0 Calling skb_gso_segment() with gso_size=0 creates over 32000 tiny segments from a single GSO skb. This floods the TX ring with ~1024 micro-frames (the rest are purged), creating a massive burst of TX completion events that can lead to memory corruption and a subsequent use-after-free in TCP's retransmit queue (refcount underflow in tcp_shifted_skb, NULL deref in tcp_rack_detect_loss). The MVM driver is immune because it checks mvmsta->amsdu_enabled before reaching the num_subframes calculation. The MLD driver has no equivalent bitmap check and relies solely on max_tid_amsdu_len, which does not catch the sentinel value. Fix this by detecting the sentinel value (max_tid_amsdu_len == 1) at the existing check and falling back to non-AMSDU TSO segmentation. Also add a WARN_ON_ONCE guard after the num_subframes division as defense-in-depth to catch any future code paths that produce zero through a different mechanism.
CVE-2026-100075CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: RDMA/srpt: Fix srpt_alloc_rw_ctxs() unwind counters When srpt_alloc_rw_ctxs() fails partway through a multi-buffer indirect descriptor, the unwind path destroys RDMA contexts but leaves stale n_rw_ctx and n_rdma values (and a dangling rw_ctxs pointer). Later sq_wr_avail accounting in srpt_queue_response() or srpt_write_pending() can then subtract the wrong number of send queue credits. Reset the counters and clear rw_ctxs after freeing the heap allocation before returning an error.
CVE-2026-64035CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: igc: set tx buffer type for SMD frames Sashiko pointed out that igc_fpe_init_smd_frame() initializes igc_tx_buffer fields for an SMD skb, but does not set the buffer type: https://sashiko.dev/#/patchset/20260415025226.114115-1-kohei%40enjuk.jp Since igc_tx_buffer entries are reused, a stale XDP or XSK type can remain and make TX completion use the wrong cleanup path. Set the buffer type to IGC_TX_BUFFER_TYPE_SKB.
CVE-2026-64007CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: netfilter: synproxy: refresh tcphdr after skb_ensure_writable synproxy_tstamp_adjust() rewrites the TCP timestamp option in place and then patches the TCP checksum via inet_proto_csum_replace4() on the caller-supplied tcphdr pointer. Both ipv4_synproxy_hook() and ipv6_synproxy_hook() obtain that pointer with skb_header_pointer() before calling in, so it may either alias skb->head directly or point at the caller's on-stack _tcph buffer. Between obtaining the pointer and using it, the function calls skb_ensure_writable(skb, optend), which on a cloned or non-linear skb invokes pskb_expand_head() and frees the old skb->head. After that point the cached th is stale: caller (ipv[46]_synproxy_hook) th = skb_header_pointer(skb, ..., &_tcph) synproxy_tstamp_adjust(skb, protoff, th, ...) skb_ensure_writable(skb, optend) pskb_expand_head() /* kfree(old skb->head) */ ... inet_proto_csum_replace4(&th->check, ...) /* writes into freed head, or into the caller's stack copy leaving the on-wire checksum stale */ The option bytes are written through skb->data and are fine; only the checksum update goes through th and so lands in the wrong place. The result is either a write into freed slab memory or a packet leaving with a checksum that does not match its payload. Fix by re-deriving th from skb->data + protoff immediately after skb_ensure_writable() succeeds, so the subsequent checksum update targets the linear, writable header.

References

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