What’s Vulnerable › Vulnerabilities

CVE-2026-53158: misc: fastrpc: Fix NULL pointer dereference in rpmsg callback

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-25 · updated 2026-07-07
• Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: Fix NULL pointer dereference in rpmsg callback A NULL pointer dereference was observed on Hawi at boot when the DSP sends a glink message before fastrpc_rpmsg_probe() has completed initialization: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000178 pc : _raw_spin_lock_irqsave+0x34/0x8c lr : fastrpc_rpmsg_callback+0x3c/0xcc [fastrpc] ... Call trace: _raw_spin_lock_irqsave+0x34/0x8c (P) fastrpc_rpmsg_callback+0x3c/0xcc [fastrpc] qcom_glink_native_rx+0x538/0x6a4 qcom_glink_smem_intr+0x14/0x24 [qcom_glink_smem] The faulting address 0x178 corresponds to the lock variable inside struct fastrpc_channel_ctx, confirming that cctx is NULL when fastrpc_rpmsg_callback() attempts to take the spinlock. There are two issues here. First, dev_set_drvdata() is called before spin_lock_init() and idr_init(), leaving a window where the callback can retrieve a valid cctx pointer but operate on an uninitialized spinlock. Second, the rpmsg channel becomes live as soon as the driver is bound, so fastrpc_rpmsg_callback() can fire before dev_set_drvdata() is called at all, resulting in dev_get_drvdata() returning NULL. Fix both issues by moving all cctx initialization ahead of dev_set_drvdata() so the structure is fully initialized before it becomes visible to the callback, and add a NULL check in fastrpc_rpmsg_callback() as a guard against any remaining window.

Affected products

• Linux kernel: from 5.1 before 5.10.260; from 5.11 before 5.15.211; from 5.16 before 6.1.177; from 6.2 before 6.6.143; from 6.7 before 6.12.94; from 6.13 before 6.18.36 — fixed in 5.10.260, 5.15.211, 6.1.177, 6.12.94, 6.18.36, 6.6.143

How to fix

Upgrade to a fixed version: Linux kernel 5.10.260, 5.15.211, 6.1.177, 6.12.94. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/0d8c64511fd45690c5326f013710efcb4f73a97e
• https://git.kernel.org/stable/c/150bf6f1193c69252580c19d3b3cd631ddce61d7
• https://git.kernel.org/stable/c/4bfdf0a9855df55e9e031ca6a25b855820590c70
• https://git.kernel.org/stable/c/5401fb4fe10fac6134c308495df18ed74aebb9c4
• https://git.kernel.org/stable/c/8fb4a23df5b7c02929b62e5dbc270ec7c42b8134
• https://git.kernel.org/stable/c/a3d91218ccca1e990bfb737b5a6da23f0afba22b
• https://git.kernel.org/stable/c/d5de9cb5355db36438edc621dde3673e3f235767
• https://git.kernel.org/stable/c/d77583ca33299fede0c194744ef2284e7ba5b763

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