CVE-2021-47077 scsi: qedf: Add pointer checks in qedf_update_link_speed()
A missing null pointer check in the Linux kernel's qedf driver can cause a system crash when updating link speed.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-47077?
CVE-2021-47077 is a medium-severity vulnerability in Linux kernel, published on 1 Mar 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
scsi: qedf: Add pointer checks in qedf_update_link_speed()
The following trace was observed:
[ 14.042059] Call Trace: [ 14.042061] <IRQ> [ 14.042068] qedf_link_update+0x144/0x1f0 [qedf] [ 14.042117] qed_link_update+0x5c/0x80 [qed] [ 14.042135] qed_mcp_handle_link_change+0x2d2/0x410 [qed] [ 14.042155] ? qed_set_ptt+0x70/0x80 [qed] [ 14.042170] ? qed_set_ptt+0x70/0x80 [qed] [ 14.042186] ? qed_rd+0x13/0x40 [qed] [ 14.042205] qed_mcp_handle_events+0x437/0x690 [qed] [ 14.042221] ? qed_set_ptt+0x70/0x80 [qed] [ 14.042239] qed_int_sp_dpc+0x3a6/0x3e0 [qed] [ 14.042245] tasklet_action_common.isra.14+0x5a/0x100 [ 14.042250] __do_softirq+0xe4/0x2f8 [ 14.042253] irq_exit+0xf7/0x100 [ 14.042255] do_IRQ+0x7f/0xd0 [ 14.042257] common_interrupt+0xf/0xf [ 14.042259] </IRQ>
API qedf_link_update() is getting called from QED but by that time shost_data is not initialised. This results in a NULL pointer dereference when we try to dereference shost_data while updating supported_speeds.
Add a NULL pointer check before dereferencing shost_data.
Weakness: CWE-476
Which versions are affected by CVE-2021-47077?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2021-47077?
Apply the vendor's patch.
Is CVE-2021-47077 being exploited?
There is no known exploitation of CVE-2021-47077 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2021-47077, GHSA-xcfc-r834-76g4, UBUNTU-CVE-2021-47077.