CVE-2022-49940 Information

Jun 19, 2025 cve

Description

In the Linux kernel the following vulnerability has been resolved:

tty: n_gsm: add sanity check for gsm->receive in gsm_receive_buf()

A null pointer dereference can happen when attempting to access the \gsm->receive()\ function in gsmld_receive_buf(). Currently the code assumes that gsm->recieve is only called after MUX activation. Since the gsmld_receive_buf() function can be accessed without the need to initialize the MUX the gsm->receive() function will not be set and a NULL pointer dereference will occur.

Fix this by avoiding the call to \gsm->receive()\ in case the function is not initialized by adding a sanity check.

Call Trace: gsmld_receive_buf+0x1c2/0x2f0 drivers/tty/n_gsm.c:2861 tiocsti drivers/tty/tty_io.c:2293 [inline] tty_ioctl+0xa75/0x15d0 drivers/tty/tty_io.c:2692 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 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+0x63/0xcd

Reference

https://git.kernel.org/stable/c/309aea4b6b813f6678c3a547cfd7fe3a76ffa976 https://git.kernel.org/stable/c/5a82cf64f8ad63caf6bf115642ce44ddbc64311e https://git.kernel.org/stable/c/5aa37f9510345a812c0998bcbbc4d88d1dcc4d8b https://git.kernel.org/stable/c/f16c6d2e58a4c2b972efcf9eb12390ee0ba3befb

CNNVD-202506-2225 (Published: 2025-06-18)

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