CVE-2026-53402fbdev: fbcon: fix out-of-bounds read in err_out of fbcon_do_set_font()
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: fbdev: fbcon: fix out-of-bounds read in err_out of fbcon_do_set_font() When fbcon_do_set_font() fails (e.g., due to a memory allocation failure inside vc_resize() under heavy memory pressure), it jumps to the `err_out` label to roll back the console state. However, the current rollback logic forgets to restore the `hi_font` state, leading to a severe state machine corruption. Earlier in the function, `set_vc_hi_font()` might be called to change `vc->vc_hi_font_mask` and mutate the screen buffer. If `vc_resize()` subsequently fails, the `err_out` path restores `vc_font.charcount` but entirely skips rolling back the `vc_hi_font_mask` and the screen buffer. This mismatch leaves the terminal in a desynchronized state. Because `vc_hi_font_mask` remains set, the VT subsystem will still accept character indices greater than 255 from userspace and write them to the screen buffer. Subsequent rendering calls (e.g., `fbcon_putcs()`) will then use these inflated indices to access the reverted, 256-character font array, leading to a deterministic out-of-bounds read and potential kernel memory disclosure. Fix this by adding the missing rollback logic for the `hi_font` mask and screen buffer in the error path.
- CVSS
- 7.1 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Analyzed
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 868749a7456dc48e93887a8474194e2ee6d6c21f before cb016bcb40c81e7b19c4ae6143babb366dae8e20; from ebd6f886aa2447fcfcdce5450c9e1028e1d681bb before ac562193c36696513ae196171892e9338475c4bc; from a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 before 3618a4c5b2591cfa83efe74f5b18c2d02b35c3f5; from a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 before a7a526fbc847f07ad3a503c7382189be5ab68574; from a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 before b5bb2c696e140c399cb874def2feedf61dee27d6; from a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 before 076b1aa65f77a49bce5a48a4a55a397cfcafa2b8; from a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 before 39815715cbcfabb16fc8c5f4a23deeda20f5df62; from a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 before 8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2; and 4 more ranges | CNA record |
linux linux_kernel linux:linux_kernel | from 5.10.249 before 5.10.261; from 5.15.64 before 5.15.212; from 5.19.6 before 6.0; from 6.0.1 before 6.1.178; from 6.2 before 6.6.145; from 6.7 before 6.12.96; from 6.13 before 6.18.39; from 6.19 before 7.1.3; and 6 more ranges | NVD |
References
- https://git.kernel.org/stable/c/cb016bcb40c81e7b19c4ae6143babb366dae8e20patch
- https://git.kernel.org/stable/c/ac562193c36696513ae196171892e9338475c4bcpatch
- https://git.kernel.org/stable/c/3618a4c5b2591cfa83efe74f5b18c2d02b35c3f5patch
- https://git.kernel.org/stable/c/a7a526fbc847f07ad3a503c7382189be5ab68574patch
- https://git.kernel.org/stable/c/b5bb2c696e140c399cb874def2feedf61dee27d6patch
- https://git.kernel.org/stable/c/076b1aa65f77a49bce5a48a4a55a397cfcafa2b8patch
- https://git.kernel.org/stable/c/39815715cbcfabb16fc8c5f4a23deeda20f5df62patch
- https://git.kernel.org/stable/c/8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.