| Age | Commit message (Collapse) | Author | Files | Lines |
|---|
|
[ Upstream commit 061db6b7a910b8378f3b2df64f8c0a3ddc6e85f2 ]
show_mode(), show_modes(), and store_mode() access fb_info->modelist
and fb_info->mode without holding lock_fb_info(). store_modes() takes
lock_fb_info() while replacing the modelist and freeing the old one.
A concurrent reader or writer can load a pointer to an old modelist
entry before store_modes() frees it, then dereference freed memory or
store a stale freed pointer in fb_info->mode.
Take lock_fb_info() in show_mode(), show_modes(), and store_mode() to
serialize with store_modes(). In show_mode(), copy the mode to the
stack and format after dropping the lock. In store_mode(), split
activate() into a _locked variant to avoid double-locking, and hold
the locks for the modelist walk, mode conversion, activation, and
fb_info->mode assignment together.
Cc: stable@vger.kernel.org # v7.1+
Signed-off-by: Melbin K Mathew <mlbnkm1@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
[ Upstream commit 6f611e5e5f3327cf2e2daabe6ee5acac58cc784e ]
Handle fbcon during display updates in fb_set_var_from_user(). Check
with fbcon if the mode change is possible, update hardware state and
finally update fbcon. Update all callers.
Only the FBIOPUT_VSCREENINFO ioctl currently does all steps. Other
mode-changes callers in sysfs and driver code are missing fbcon-related
steps.
With the new helper, ps3fb and sh_mobile_lcdcfb no longer maintain
fbcon state themselves.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Stable-dep-of: 061db6b7a910 ("fbdev: serialize mode sysfs access with lock_fb_info()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 81cc73be40c6f028f1ee3f438ace46afe666dbae upstream.
In fb_io_read(), if copy_to_user() performs a partial copy (e.g., due to
a faulty user buffer), the loop adjusts the chunk size 'c' and updates
the remaining 'count'. However, the hardware 'src' pointer has already
been eagerly advanced by the original chunk size.
If the loop is allowed to continue, the read will resume from an
incorrect, over-advanced offset. Since the remaining 'count' was only
decremented by the successful bytes, this desynchronization causes the
next iterations to execute more hardware reads than originally bounded,
eventually leading to out-of-bounds I/O reads.
Fix this by breaking out of the loop immediately upon a partial
copy_to_user(). A partial copy indicates a faulty user buffer, making
subsequent read attempts futile. Breaking out ensures we return the
number of successfully read bytes without risking out-of-bounds hardware
accesses in subsequent mismatched iterations.
Fixes: 6121cd9ef911 ("fbdev: Move I/O read and write code into helper functions")
Cc: stable@vger.kernel.org
Signed-off-by: Mingyu Wang <25181214217@stu.xidian.edu.cn>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 95e647d2a5304a8fd11f1ba3c8502de700650131 upstream.
fb_set_var() can delete a mode from info->modelist when userspace
passes FB_ACTIVATE_INV_MODE through FBIOPUT_VSCREENINFO. The code
checks that the mode being deleted is not the current info->var and
that fbcon is not using it, but it does not check fb_info->mode.
fb_info->mode may still point into the modelist entry being deleted.
If the entry is freed, later mode sysfs reads through show_mode() can
dereference a stale pointer.
Clear fb_info->mode before calling fb_delete_videomode() when it
matches the mode being removed.
Cc: stable@vger.kernel.org # v7.1+
Signed-off-by: Melbin K Mathew <mlbnkm1@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit d15d51fb26e830af58f3f21964f1c09c239077ea upstream.
mode_string() uses snprintf() which can return a value larger than the
remaining buffer space. show_modes() accumulates the return value into i
without checking whether i has reached PAGE_SIZE, causing the offset to
advance past the sysfs buffer if the modelist is long enough.
Add a size parameter to mode_string() and use scnprintf() to return
only the bytes actually written. Add an early return when offset
already exceeds the buffer. In show_modes(), stop accumulating once
the buffer is full.
Cc: stable@vger.kernel.org # v7.1+
Signed-off-by: Melbin K Mathew <mlbnkm1@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit e033cbf3975a8465f879ebd5989dc35b04423a4d upstream.
bit_cursor() fetches the glyph under the cursor with
c = scr_readw(vc_pos);
src = vc_font.data + ((c & charmask) * w * height);
where charmask is 0x1ff when vc_hi_font_mask is set. The screen buffer
value comes directly from scr_readw() and may be larger than the current
font's glyph count.
Syzkaller triggers this via vcs_write(). The Call Trace shows
vcs_write() in vc_screen.c writing an arbitrary 16-bit value with
writev() to /dev/vcsa, which vcs_write_buf() in vc_screen.c stores via
vcs_scr_writew() without checking charcount. The stored value is later
read in bit_cursor() in bitblit.c.
When the font is changed from a font with 512 glyphs to a font with
256 glyphs, the screen buffer can retain characters with the high
bit set from the previous mode, which could also produce the same
out-of-bounds access.
BUG: KASAN: global-out-of-bounds in soft_cursor+0x378/0x6bc drivers/video/fbdev/core/softcursor.c:70
Read of size 16 at addr ffff800086c57970
Call Trace:
soft_cursor+0x378/0x6bc drivers/video/fbdev/core/softcursor.c:70
bit_cursor+0xa90/0x1108 drivers/video/fbdev/core/bitblit.c:365
fbcon_cursor+0x344/0x498 drivers/video/fbdev/core/fbcon.c:1427
hide_cursor+0xdc/0x2d0 drivers/tty/vt/vt.c:883
update_region+0x100/0x18c drivers/tty/vt/vt.c:669
vcs_write+0x8ec/0xaf0 drivers/tty/vt/vc_screen.c:685
bit_putcs_aligned() and bit_putcs_unaligned() already clamp the glyph
index to vc_font.charcount. Apply the same clamp in bit_cursor() after
extracting the attribute and masking, before indexing fontdata.
The fix completes the bounds checking started in commit 18c4ef4e765a
("fbdev: bitblit: bound-check glyph index in bit_putcs*"), which missed
the cursor path.
This change should be safe because the clamp reuses the existing
contract from fbcon: charcount is maintained under console_lock in
con_font_set() and fbcon_font_set(), and hi_font_mask is cleared when
switching from 512 to 256 glyphs. When stale screen data with high bits
remains after a font switch, or when vcs_write() stores an arbitrary
value, clamping the index to 0 prevents the out-of-bounds read without
changing cursor semantics — the same fallback bit_putcs uses.
Reported-by: syzbot+61b1db46218109869c14@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=61b1db46218109869c14
Link: https://lore.kernel.org/all/6a75205c.01d0871a.3a0d52.0032.GAE@google.com/
Fixes: 18c4ef4e765a ("fbdev: bitblit: bound-check glyph index in bit_putcs*")
Cc: stable@vger.kernel.org
Assisted-by: Hermes:muse-spark-1.2 syzkaller
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 7a35ec619d9af8ee128320975c1252b8ad65f1e8 upstream.
In trident_pci_probe(), the memory allocated for modelist using
fb_videomode_to_modelist() is not freed in subsequent error paths.
Fix that by calling fb_destroy_modelist().
Fixes: 6a5e3bd0c8bc ("tridentfb: Add DDC support")
Cc: stable@vger.kernel.org
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 85f5e38c162bdf9dbbe197275d416402712f3707 upstream.
In nvidiafb_probe(), the memory allocated for modelist in
nvidia_set_fbinfo() is not freed in the subsequent error paths.
Fix that by calling fb_destroy_modelist().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit b15d708995c01bbffe7dcd634a31959f6805bed3 upstream.
Since commit 73ce73c30ba9 ("fbdev: Transfer video= option strings to
caller; clarify ownership") the string returned from fb_get_options()
is expected to be freed by the caller. But the string is not freed in
vesafb_probe(). Fix that by freeing the option string after setup.
Fixes: 73ce73c30ba9 ("fbdev: Transfer video= option strings to caller; clarify ownership")
Cc: stable@vger.kernel.org
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 6fcca16a2b19c37f60693c56cbc0c923364ff3ef upstream.
The memory allocated for modelist in fb_videomode_to_modelist() is not
freed in the subsequent error path.
Fix that by calling fb_destroy_modelist()
Fixes: 2ece5f43b041 ("fbdev: add the carmine FB driver")
Cc: stable@vger.kernel.org
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit bb019d755366cc3e777a12d4bf457ff289837370 upstream.
In tdfxfb_probe(), the memory allocated for modelist using
fb_videomode_to_modelist() when CONFIG_FB_3DFX_I2C is defined, is not
freed in the subsequent error paths.
Fix that by calling fb_destroy_modelist().
Fixes: 215059d2421f ("tdfxfb: make use of DDC information about connected monitor")
Cc: stable@vger.kernel.org
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 033e56fed09047ee63072e9f58789f40c1c7079d upstream.
Due to an incorrect goto label, memory allocated for modedb and modelist
in uvesafb_vbe_init() is not freed in some error paths. Fix this by
updating the goto label.
Fixes: 8bdb3a2d7df4 ("uvesafb: the driver core")
Cc: stable@vger.kernel.org
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 3b0ed04bc852887a9164e1bbf521652e8ef3eb92 upstream.
In s3_pci_probe(), the memory allocated for modelist using
fb_videomode_to_modelist() is not freed in subsequent error paths.
Fix that by calling fb_destroy_modelist()
Fixes: 86c0f043a737 ("s3fb: add DDC support")
Cc: stable@vger.kernel.org
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 5936063409af230a2c88b8700c47b89a19fd70b5 upstream.
In i740fb_probe(), the memory allocated in fb_videomode_to_modelist()
for modelist is not freed in the error paths. Fix that by calling
fb_destroy_modelist().
Fixes: 5350c65f4f15 ("Resurrect Intel740 driver: i740fb")
Cc: stable@vger.kernel.org
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit df8c1101c9a08859da612b5d0a08d55d475522c6 upstream.
The function radeonfb_pci_register() allocates memory for modelist
(by calling radeon_check_modes() which calls fb_add_videomode()).
The memory is appended to info->modelist, but is not freed in subsequent
error paths. Fix this by calling fb_destroy_modelist().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 9b6eaf101656958397a6012bf43f6e2e42c9e5cb upstream.
Since commit 73ce73c30ba9 ("fbdev: Transfer video= option strings to
caller; clarify ownership") the string returned from fb_get_options()
is expected to be freed by the caller, but the string is not freed in
efifb_probe(). Fix that by freeing the option string after setup.
Fixes: 73ce73c30ba9 ("fbdev: Transfer video= option strings to caller; clarify ownership")
Cc: stable@vger.kernel.org
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 5dbe5b65df0b0c0ec77492427c274b7b5011890e upstream.
The big_swap(p) macro was intended to swap bytes within 16-bit halves
of a 32-bit value. However, because the bitwise shift operators (<<, >>)
have higher precedence than the bitwise AND operator (&), the original
code failed to perform any shifting on the masked bits.
For example, 'p & 0xff00ff00 >> 8' was evaluated as 'p &
(0xff00ff00 >> 8)', effectively neutralizing the intended swap.
Fix this by adding parentheses to ensure the bitwise AND is performed
before the shift, correctly implementing the byte swap logic.
Fixes: 1461d66728648 ("staging: sm7xxfb: merge sm712fb with fbdev")
Cc: stable@vger.kernel.org
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit cbef2a305a8a72969b86f96b7c07b86edde61aff upstream.
The memory allocated for pagerefs in fb_deferred_io_init() is not freed
on the error path. Fix it by calling fb_deferred_io_cleanup().
Fixes: 56c134f7f1b5 ("fbdev: Track deferred-I/O pages in pageref struct")
Cc: stable@vger.kernel.org
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 9d18a4e4234fd3ee0d0eed8ccbbb50cb76b2232c upstream.
The memory allocated for pagerefs in fb_deferred_io_init() is not freed
on the error path. Fix it by calling fb_deferred_io_cleanup().
Fixes: 56c134f7f1b5 ("fbdev: Track deferred-I/O pages in pageref struct")
Cc: stable@vger.kernel.org
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 894632b862a39b3fe1cb5de06fbae86225ea64de upstream.
The memory allocated for pagerefs in fb_deferred_io_init() is not freed
on the error path. Fix it by calling fb_deferred_io_cleanup().
Fixes: 56c134f7f1b5 ("fbdev: Track deferred-I/O pages in pageref struct")
Cc: stable@vger.kernel.org
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
[ Upstream commit d8421e09382cfe0bd2a044c8b0a822f64855dd4e ]
The code that gets the frame buffer mode from OF has 'use after free',
'buffer overrun' and memory leaks.
info->edid_data isn't free if the probe functions fail or if
pd->def_mode is set.
If both the CRT and PANEL are enabled info->edid_data is used after
being freed and is freed twice.
The string returned by of_get_property(np, "mode", &len) is just
written over either the static "640x480-16@60" or the module parameter
string without any regard for the length (which is most likely longer).
Use kstrump() for the OF mode and free everything before freeing 'info.
Fixes: 4295f9bf74a88 ("video, sm501: add OF binding to support SM501")
Signed-off-by: David Laight <david.laight.linux@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
commit 84202754fb1727dc3ee87f47104e4162ecc8ba3a upstream.
The return value of vc_resize() is int, but fbcon_set_disp() stores it
in an unsigned long variable. While the !ret check happens to work
correctly by coincidence (negative values become large positive values),
the types should match. Use int instead.
Eliminates the following W=3 warning:
drivers/video/fbdev/core/fbcon.c: In function 'fbcon_set_disp':
drivers/video/fbdev/core/fbcon.c:1494:14: warning: implicit conversion from 'int' to 'unsigned long' [-Wconversion]
Fixes: af0db3c1f898 ("fbdev: Fix vmalloc out-of-bounds write in fast_imageblit")
Cc: stable@vger.kernel.org # v6.17+
Signed-off-by: Jiacheng Yu <yujiacheng3@huawei.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 5fae9a928482d4845bca169a3a098789203a1ca4 upstream.
fbcon_new_modelist() runs when a framebuffer's modelist changes. For each
console mapped to it with fb_display[i].mode set, it reads vc_cons[i].d and
passes the vc_num to fbcon_set_disp(). This assumes a console with a mode
set has a vc_data, but it can be NULL. fbcon_set_disp() sets
fb_display[i].mode before it checks vc_data, and fbcon_deinit() leaves the
mode set after the vc_data is freed. fbcon_new_modelist() then dereferences
the NULL vc_data.
Keep fb_display[i].mode set only while the console has a vc_data. Check
vc_data before setting the mode in fbcon_set_disp(), and clear the mode in
fbcon_deinit(). The existing mode check in fbcon_new_modelist() then skips
such consoles.
Reported-by: syzbot+42525d636f430fd5d983@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=42525d636f430fd5d983
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Ian Bridges <icb@fastmail.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit d894c48a57d78206e4df9c90d4acfaf39394806a upstream.
The 1920x1080@60 modedb entry has one too many initializers before
its sync field: a stray "0" occupies the sync slot, which shifts the
remaining values by one field. The entry therefore decodes as
sync = 0, vmode = FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT (0x3,
i.e. FB_VMODE_INTERLACED | FB_VMODE_DOUBLE), and flag =
FB_VMODE_NONINTERLACED, instead of the intended sync = positive H/V,
vmode = non-interlaced.
fb_find_mode() then returns a 1920x1080 mode flagged as interlaced +
doublescan with active-low syncs. Drivers that honour var->vmode and
var->sync when programming display timing enable doublescan and the
wrong sync polarity, corrupting the output.
Drop the stray initializer so sync and vmode hold their intended
values (positive H/V sync, non-interlaced), matching the adjacent
1920x1200 entry.
Fixes: c8902258b2b8 ("fbdev: modedb: Add 1920x1080 at 60 Hz video mode")
Cc: stable@vger.kernel.org
Signed-off-by: Steffen Persvold <spersvold@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 85b6256469cebdac395e7447147e06b2e151014f upstream.
If mode_option is NULL, it is assigned from mode_option_buf:
if (!mode_option) {
fb_get_options(NULL, &mode_option_buf);
mode_option = mode_option_buf;
}
Later, name is assigned from mode_option:
const char *name = mode_option;
However, mode_option_buf is freed before name is no longer used:
kfree(mode_option_buf);
while name is still accessed by:
if ((name_matches(db[i], name, namelen) ||
Since name aliases mode_option_buf, this may result in a
use-after-free.
Fix this by extending the lifetime of mode_option_buf until the end of the
function by using scope-based resource management for cleanup.
Signed-off-by: Tuo Li <islituo@gmail.com>
Cc: stable@vger.kernel.org # v6.5+
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 7958e67375aa111522086286bba13cfc0816ce8d upstream.
omapfb_mmap() has a race condition with OMAPFB_SETUP_PLANE ioctl that
can lead to use-after-free:
The fb_mmap() entry point holds mm_lock but not lock (fb_info->lock),
while ioctl handlers like OMAPFB_SETUP_PLANE hold lock but not mm_lock.
This allows concurrent execution.
In omapfb_mmap():
1. rg = omapfb_get_mem_region(ofbi->region); // Get old region ref
2. start = omapfb_get_region_paddr(ofbi); // Read from NEW region
3. len = fix->smem_len; // Read from NEW region
4. vm_iomap_memory(vma, start, len); // Map NEW region memory
5. atomic_inc(&rg->map_count); // Increment OLD region!
Concurrently, OMAPFB_SETUP_PLANE can:
- Reassign ofbi->region = new_rg
- Update fix->smem_len
- OMAPFB_SETUP_MEM then checks NEW region's map_count (0!) and frees it
This leaves userspace with a mapping to freed physical memory.
The fix is to read all required values (start, len) from the same
region reference (rg) that will have its map_count incremented,
preventing the region from being freed while still mapped.
Cc: stable@vger.kernel.org
Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2 upstream.
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.
Fixes: a5a923038d70 ("fbdev: fbcon: Properly revert changes when vc_resize() failed")
Cc: stable@vger.kernel.org
Signed-off-by: Mingyu Wang <25181214217@stu.xidian.edu.cn>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 7f08fc10fa3d3366dc3af723970bd03d7d6d10e3 upstream.
info->var, a framebuffer's current mode, is expected to have a matching
entry in info->modelist. var_to_display() relies on this and treats a
failed fb_match_mode() as "This should not happen". fb_set_var() keeps it
true by adding the mode to the list on every change, and
do_register_framebuffer() does the same at registration.
store_modes() replaces the modelist from userspace. fb_new_modelist()
validates the new modes but does not check that info->var still has a
match. It relies on fbcon_new_modelist() to re-point consoles, but that
only handles consoles mapped to the framebuffer. With fbcon unbound there
are none, so info->var is left describing a mode that is no longer in the
list.
A later console takeover runs var_to_display(), where fb_match_mode()
returns NULL and leaves fb_display[i].mode NULL. fbcon_switch() passes it
to display_to_var(), and fb_videomode_to_var() dereferences the NULL mode.
Keep the current mode in the list in fb_new_modelist(), the same way
fb_set_var() does.
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Ian Bridges <icb@fastmail.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 2c1c805c65fb7dc7524e20376d6987721e73a0b1 upstream.
store_modes() replaces a framebuffer's modelist with modes from userspace.
On success it frees the old modelist with fb_destroy_modelist(). Two
fields still point into that freed list.
One pointer is fb_display[i].mode, the mode a console is using.
fbcon_new_modelist() moves these pointers to the new list. It only does so
for consoles still mapped to the framebuffer. An unmapped console is
skipped and keeps its stale pointer. Unbinding fbcon, for example, sets
con2fb_map[i] to -1 but leaves fb_display[i].mode set. An
FBIOPUT_VSCREENINFO ioctl with FB_ACTIVATE_INV_MODE later reaches
fbcon_mode_deleted(). That function reads the stale fb_display[i].mode
through fb_mode_is_equal(). The read is a use-after-free.
The other pointer is fb_info->mode, the current mode. It is set through
the mode sysfs attribute. store_modes() does not update fb_info->mode, so
it is left pointing into the freed list. show_mode(), the attribute's read
handler, dereferences the stale fb_info->mode through mode_string(). The
read is a use-after-free.
Clear both pointers before freeing the list. Commit a1f305893074 ("fbcon:
Set fb_display[i]->mode to NULL when the mode is released") added the
helper fbcon_delete_modelist(). It clears every fb_display[i].mode that
points into a given list. So far it is called only from the unregister
path. Call it from store_modes() too, and set fb_info->mode to NULL.
Reported-by: syzbot+81c7c6b52649fd07299d@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=81c7c6b52649fd07299d
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/ajjoDhAi2y4ArSlz@dev/
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Ian Bridges <icb@fastmail.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
dlfb_ops_mmap() uses remap_pfn_range() to map vmalloc framebuffer pages
to userspace but sets no vm_ops on the VMA. This means the kernel cannot
track active mmaps. When dlfb_realloc_framebuffer() replaces the backing
buffer via FBIOPUT_VSCREENINFO, existing mmap PTEs are not invalidated.
On USB disconnect, dlfb_ops_destroy() calls vfree() on the old pages
while userspace PTEs still reference them, resulting in a use-after-free:
the process retains read/write access to freed kernel pages.
Add vm_operations_struct with open/close callbacks that maintain an
atomic mmap_count on struct dlfb_data. In dlfb_realloc_framebuffer(),
check mmap_count and return -EBUSY if the buffer is currently mapped,
preventing buffer replacement while userspace holds stale PTEs.
Tested with PoC using dummy_hcd + raw_gadget USB device emulation.
Signed-off-by: Rajat Gupta <rajgupt@qti.qualcomm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
Remove duplicate inclusion of linux/module.h in fb_defio.c to clean up
redundant code.
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
The driver calls ioremap() on the HGA video memory at 0xb0000 without
first reserving the physical address range. This leaves the kernel
resource tree incomplete and can cause silent conflicts with other
drivers claiming the same range.
Add a devm_request_mem_region() call before ioremap() in
hga_card_detect() to reserve the memory region.
Signed-off-by: Hardik Phalet <hardik.phalet@pm.me>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
Use devm_platform_get_and_ioremap_resource() for resource 0 (the MMIO
control register range) instead of open-coding platform_get_resource()
and devm_ioremap() separately. The helper requests the memory region
before mapping it, which registers the range in /proc/iomem and prevents
another driver from mapping the same registers.
This makes resource 0 consistent with resource 1 (the framebuffer),
which already uses devm_platform_get_and_ioremap_resource().
Assisted-by: Claude:claude-sonnet-4-6
Signed-off-by: Amit Barzilai <amit.barzilai22@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
Use devm_platform_get_and_ioremap_resource() instead of open-coding
platform_get_resource() and devm_ioremap() separately. The helper
requests the memory region before mapping it, which registers the range
in /proc/iomem and prevents another driver from mapping the same
registers.
Assisted-by: Claude:claude-sonnet-4-6
Signed-off-by: Amit Barzilai <amit.barzilai22@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
Signed-off-by: Ethan Carter Edwards <ethan@ethancedwards.com>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
When CONFIG_FB_SAVAGE_I2C is enabled, savagefb_probe() can build both an
EDID-derived monspecs.modedb and a modelist from it before later failing.
The normal success path frees monspecs.modedb after the initial mode selection,
but the probe error path only deletes the I2C busses and misses the
EDID-derived allocations.
Free both the modelist and monspecs.modedb on the failed: unwind path.
Co-developed-by: Myeonghun Pak <mhun512@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Co-developed-by: Taegyu Kim <tmk5904@psu.edu>
Signed-off-by: Taegyu Kim <tmk5904@psu.edu>
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
offb_init_nodriver() gets a referenced PCI device with pci_get_device().
If pci_enable_device() fails, the function returns without dropping that
reference.
Release the PCI device reference before returning from the
pci_enable_device() failure path.
Fixes: 5bda8f7b5468 ("video: fbdev: offb: Call pci_enable_device() before using the PCI VGA device")
Co-developed-by: Myeonghun Pak <mhun512@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Co-developed-by: Taegyu Kim <tmk5904@psu.edu>
Signed-off-by: Taegyu Kim <tmk5904@psu.edu>
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
Much like commit 19f953e74356 ("fbdev: fb_pm2fb: Avoid potential divide
by zero error"), we also need to prevent that same crash from happening
in the udlfb driver as it uses pixclock directly when dividing, which
will crash.
Cc: Bernie Thompson <bernie@plugable.com>
Cc: Helge Deller <deller@gmx.de>
Fixes: 59277b679f8b ("Staging: udlfb: add dynamic modeset support")
Assisted-by: gregkh_clanker_t1000
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
Much like commit 19f953e74356 ("fbdev: fb_pm2fb: Avoid potential divide
by zero error"), we also need to prevent that same crash from happening
in the udlfb driver as it uses pixclock directly when dividing, which
will crash.
Cc: Helge Deller <deller@gmx.de>
Assisted-by: gregkh_clanker_t1000
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
Fix the warning about inconsistent returns for '&rg->lock' in
omapfb_mmap() function. The warning arises because the error path
uses 'ofbi->region' while the normal path uses 'rg'.
smatch warnings:
drivers/video/fbdev/omap2/omapfb/omapfb-main.c:1126 omapfb_mmap()
warn: inconsistent returns '&rg->lock'.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
Move all temporary state of the font-rotation code into the struct
rotated in struct fbcon_par. Protect it with the Kconfig symbol
CONFIG_FRAMEBUFFER_CONSOLE_ROTATION. Avoids mixing it up with fbcon's
regular state.
v2:
- fix typos
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
Fbcon creates a cursor shape on the fly from the user-configured
settings. The logic to create a glyph with the cursor's bitmap mask
is duplicated in four places. In the cases that involve console
rotation, the implementation further rotates the cursor glyph for
displaying.
Consolidate all cursor-mask creation in a single helper. Update the
callers accordingly. For console rotation, use the glyph helpers to
rotate the created cursor glyph to the correct orientation.
v2:
- fix sparse truncated-bits warning
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
Move the core of fbcon's font-rotation code to the font library as
the new helper font_data_rotate(). The code can rotate in steps of
90°. For completeness, it also copies the glyph data for multiples
of 360°.
Bring back the memset optimization. A memset to 0 again clears the
whole glyph output buffer. Then use the internal rotation helpers on
the cleared output. Fbcon's original implementation worked like this,
but lost it during refactoring.
Replace fbcon's font-rotation code with the new implementations.
All that's left to do for fbcon is to maintain its internal fbcon
state.
v2:
- fix typos
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
Move the glyph rotation helpers from fbcon to the font library. Wrap them
behind clean interfaces. Also clear the output memory to zero. Previously,
the implementation relied on the caller to do that.
Go through the fbcon code and callers of the glyph-rotation helpers. In
addition to the font rotation, there's also the cursor code, which uses
the rotation helpers.
The font-rotation relied on a single memset to zero for the whole font.
This is now multiple memsets on each glyph. This will be sorted out when
the font library also implements font rotation.
Building glyph rotation in the font library still depends on
CONFIG_FRAMEBUFFER_CONSOLE_ROTATION=y. If we get more users of the code,
we can still add a dedicated Kconfig symbol to the font library.
No changes have been made to the actual implementation of the rotate_*()
and pattern_*() functions. These will be refactored as separate changes.
v2:
- fix typos
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
Implement pitch and size calculation for a single font glyph in the
new helpers font_glyph_pitch() and font_glyph_size(). Replace the
instances where the calculations are open-coded.
Note that in the case of fbcon console rotation, the parameters for
a glyph's width and height might be reversed. This is intentional.
v2:
- fix typos in commit message
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
Clear the font buffer if the reallocation during console rotation fails
in fbcon_rotate_font(). The putcs implementations for the rotated buffer
will return early in this case. See [1] for an example.
Currently, fbcon_rotate_font() keeps the old buffer, which is too small
for the rotated font. Printing to the rotated console with a high-enough
character code will overflow the font buffer.
v2:
- fix typos in commit message
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 6cc50e1c5b57 ("[PATCH] fbcon: Console Rotation - Add support to rotate font bitmap")
Cc: stable@vger.kernel.org # v2.6.15+
Link: https://elixir.bootlin.com/linux/v6.19/source/drivers/video/fbdev/core/fbcon_ccw.c#L144 # [1]
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
With clang and W=1:
drivers/video/fbdev/aty/atyfb_base.c:2327:24: warning: variable 'fb_list' set but not used [-Wunused-but-set-global]
2327 | static struct fb_info *fb_list = NULL;
Indeed, the last user of fb_list was removed in 2004, while the actual
linked list was removed in 2002.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202603300931.osMYxYZ7-lkp@intel.com/
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
Clang is not happy about set but unused variable:
drivers/video/fbdev/matrox/g450_pll.c:412:18: error: variable 'mnp' set but not used
412 | unsigned int mnp;
| ^
1 error generated.
Since the commit 7b987887f97b ("video: fbdev: matroxfb: remove dead code
and set but not used variable") the 'mnp' became unused, but eliminating
that code might have side-effects. The question here is what should we do
with 'mnp'? The easiest way out is just mark it with __maybe_unused which
will shut the compiler up and won't change any possible IO flow. So does
this change.
A dive into the history of the driver:
The problem was revealed when the #if 0 guarded code along with unused
pixel_vco variable was removed. That code was introduced in the original
commit 213d22146d1f ("[PATCH] (1/3) matroxfb for 2.5.3"). And then guarded
in the commit 705e41f82988 ("matroxfb DVI updates: Handle DVI output on
G450/G550. Powerdown unused portions of G450/G550 DAC. Split G450/G550 DAC
from older DAC1064 handling. Modify PLL setting when both CRTCs use same
pixel clocks.").
NOTE: The two commits mentioned above pre-date Git era and available in
history.git repository for archaeological purposes.
Even without that guard the modern compilers may see that the pixel_vco
wasn't ever used and seems a leftover after some debug or review made
25 years ago.
The g450_mnp2vco() doesn't have any IO and as Jason said doesn't seem
to have any side effects either than some unneeded CPU processing during
runtime. I agree that's unlikely that timeout (or heating up the CPU) has
any effect on the HW (GPU/display) functionality.
Fixes: 7b987887f97b ("video: fbdev: matroxfb: remove dead code and set but not used variable")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
The help text for CONFIG_FB_NVIDIA refers to obsolete hardware and
incorrect default behaviour. This patch updates the description to
reflect the current state of the driver and supported devices.
Signed-off-by: robgithub <rob.github@jumpstation.co.uk>
Signed-off-by: Helge Deller <deller@gmx.de>
|
|
The hwa742_init() function did not check the return value of clk_get().
This could lead to dereferencing an error pointer in subsequent clock
operations, potentially causing a kernel crash.
Fix this by adding a missing error check and ensuring proper clock
resource cleanup on failure and driver removal.
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Signed-off-by: Helge Deller <deller@gmx.de>
|
